Pushpam
@tnau.ac.in
Associate Professor
Tamil Nadu Agricultural University
RESEARCH INTERESTS
Rice Breeding
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Kathiresan Pravin Kumar, Ramamoorthy Pushpam, Swaminathan Manonmani, Muthurajan Raveendran, Subramanian Santhiya, and Alagarsamy Senthil
Frontiers Media SA
Under changing climatic conditions, crop plants are more adversely affected by a combination of various abiotic stresses than by a single abiotic stress. Therefore, it is essential to identify potential donors to multiple abiotic stresses for developing climate-resilient crop varieties. Hence, the present study was undertaken with 41 germplasm accessions comprising native landraces of Tamil Nadu, Prerelease lines and cultivars were screened independently for drought, salinity, and submergence at the seedling stage during Kharif and Rabi 2022–2023. Stress was imposed separately for these three abiotic stresses on 21-day-old seedlings and was maintained for 10 days. The studied genotypes showed a significant reduction in plant biomass (PB), Relative Growth Index (RGI), relative water content (RWC), leaf photosynthesis, chlorophyll fluorescence, and Chlorophyll Concentration Index (CCI) under drought followed by salinity and submergence. Stress-tolerant indices for drought, salinity, and submergence revealed significant variation for plant biomass. Furthermore, a set of 30 SSR markers linked to drought, salinity, and submergence QTLs has been used to characterize 41 rice germplasm accessions. Our analysis suggests a significantly high polymorphism, with 28 polymorphic markers having a 93.40% in 76 loci. The mean values of polymorphic information content (PIC), heterozygosity index (HI), marker index (MI), and resolving power (RP) were 0.369, 0.433, 1.140, and 2.877, respectively. Jaccard clustering grouped all the genotypes into two major and six subclusters. According to STRUCTURE analysis, all genotypes were grouped into two major clusters, which are concurrent with a very broad genetic base (K = 2). Statistically significant marker-trait associations for biomass were observed for five polymorphic markers, viz., RM211, RM212 (drought), RM10694 (salinity), RM219, and RM21 (submergence). Similarly, significant markers for relative shoot length were observed for RM551 (drought), RM10694 (salinity), and ART5 (submergence). Notably, the genotypes Mattaikar, Varigarudan samba, Arupatham samba, and APD19002 were identified as potential donors for multiple abiotic stress tolerance. Thus, identifying the genetic potential of germplasm could be useful for enhancing stress resilience in rice.
Arunachalam Arun, Annaiyan Shanthi, Muthurajan Raveendran, Nagachandrabose Seenivasan, Ramamoorthy Pushpam, and Ganeshan Shandeep
MDPI AG
Rice (Oryza sativa L.) is one of the most widely grown crops in the world, and is a staple food for more than half of the global total population. Root-knot nematodes (RKNs), Meloidogyne spp., and especially M. graminicola, seem to be significant rice pests, which makes them the most economically important plant-parasitic nematode in this crop. RKNs develop a feeding site in galls by causing host cells to differentiate into hypertrophied, multinucleate, metabolically active cells known as giant cells. This grazing framework gives the nematode a constant food source, permitting it to develop into a fecund female and complete its life cycle inside the host root. M. graminicola effector proteins involved in nematode parasitism, including pioneer genes, were functionally characterized in earlier studies. Molecular modelling and docking studies were performed on Meloidogyne graminicola protein targets, such as β-1,4-endoglucanase, pectate lyase, phospholipase B-like protein, and G protein-coupled receptor kinase, to understand the binding affinity of Beta-D-Galacturonic Acid, 2,6,10,15,19,23-hexamethyltetracosane, (2S)-2-amino-3-phenylpropanoic acid, and 4-O-Beta-D-Galactopyranosyl-Alpha-D-Glucopyranose against ligand molecules of rice. This study discovered important molecular aspects of plant–nematode interaction and candidate effector proteins that were regulated by M. graminicola-infected rice plants. To the best of our knowledge, this is the first study to describe M. graminicola’s molecular adaptation to host parasitism.
R. MEGALA, M. K. KALARANI, P. JEYAKUMAR, N. SENTHIL, and R. PUSHPAM
Gaurav Publications
Foliar application of plant growth regulators (PGRs) and nutrients are being employed increasingly as a management option in recent years. Such a new compound to be explored for stress mitigation is melatonin. Melatonin, an indoleamine compound, plays an important role in plant stress defense. Studies reveal that exogenous treatment or ectopic overexpression of melatonin biosynthetic genes improve the resistance against a series of stressors in crops. But there is still opacity about the mechanisms through which melatonin confers drought tolerance in rice. To clear this ambiguity, we studied the impact of foliar application of melatonin in rice under water-stressed conditions. A glasshouse experiment was conducted at the Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore during kharif 2021. The study focussed on standardizing the optimum melatonin concentration and disseminating the physiological traits involved in conferring melatonin-mediated drought tolerance in rice. The trial was laid in a factorial completely randomized design with six treatments imposed at panicle initiation and anthesis stages in a separate set of plants replicated four times. Drought stress was imposed at panicle initiation and anthesis by withholding water for seven days, while the absolute control was watered regularly. Foliar spray of 200 and 250 µM melatonin was given, when the absolute control and control plants were left untreated. The results interpreted that drought stress significantly altered the chlorophyll content, leaf water status, lipid peroxidation and electrolyte leakage. The exogenous application of melatonin alleviated the adversative effects of drought stress by improving the osmolyte accumulation and antioxidant enzyme activity, including catalase, superoxide dismutase and ascorbate peroxidase. Therefore, it is concluded that foliar application of 200 µM melatonin was most effective in mitigating the negative influences of drought stress in rice by enhancing the antioxidant system which effectively scavenges the drought-induced reactive oxygen species.
R. Megala, M.K. Kalarani, P. Jeyakumar, N. Senthil, R. Pushpam, and M. Umapathi
ANSF Publications
Drought stress poses a serious threat to production and nutritional security. In recent years, foliar application of plant growth regulators (PGRs) and nutrients are increasingly employed to overcome physiological constraints resulting in enhanced crop production. Melatonin is a new biomolecule recently found to ameliorate the effect of biotic and abiotic stresses in crop plants. Hence, the present experiment was conducted to assess the optimum concentration of melatonin to mitigate the adverse effect of drought stress on germination and growth components in rice variety CO-54. In this experiment, PEG-mediated drought stress (-0.5 MPa) was imposed with different concentrations of melatonin (at doses of 50, 100, 150, 200, and 250 µM) seed treatments. Together, these results indicated that 200 µM melatonin-treated seeds showed a greater germination percentage (60%), root length (12.23cm), shoot length (8.23cm), fresh and dry weight (0.126g and 0.095g), high vigor index (1910.22), promptness index (64.83), and germination stress index (100) respectively. The result of this experiment provides a shred of strong evidence suggesting that seed treatment of 200 µM melatonin could be considered an effective technique for mitigating the detrimental effects of drought by promoting seed germination and thereby increasing the growth components of seedlings in rice. The study demonstrates that melatonin can shield rice seedlings from the effects of drought stress.
F. D. P. Seeli, S. Manonmani, R. Pushpam and M. Raveendran
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
The present study was undertaken to estimate the effectiveness of selection for the yield and yield contributing traits in the BC2F3 and BC2F4 generations of drought QTL introgressed progenies of Improved White Ponni (IWP) x Apo. A positively skewed and negatively skewed platykurtic curve was observed in many of the traits in both generations indicating the influence of a large number of genes. Significant and positive intergenerational correlation and regression coefficient values were obtained for all the yield contributing characters indicating that selection can be done in these generations for isolating superior genotypes. Narrow sense heritability estimates obtained high values for the traits days to 50 per cent flowering, the number of productive tillers, filled grains per panicle and single plant yield indicating that selection will be effective for these traits in these early generations.
S. Mythili, S. Manonmani, R. Pushpam and M. Raveendran
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
In the recent years of labour and water scarcity, most of the rice cultivating areas all over the world are in a desperate need to save the resources and to find suitable alternatives so as to budge from transplanted rice cultivation. Direct seeded rice (DSR) cultivation is one of the best alternative. The vast spectrum of weeds present in this DSR ecology causes a voluminous decrease in the crop yield. In order to curtail the weeds, chemical management using broad spectrum herbicides which can control all classes of weeds is the efficient and economic way. On using broad-spectrum herbicide it may cause crop injury. In this regard TNAU has developed a novel herbicide (Imazethapyr) tolerant rice mutant (HTM Robin) through EMS mutagenesis of Nagina 22 cultivar. Robin mutant was tested across the location against the herbicide Imazethapyr and found to be tolerant and was registered at NBPGR, New Delhi. In this study the efficacy of this herbicide tolerant mutant was tested under chemical weed management. The genotypes CO51, HTM, Nagina 22 were raised in the weed free and control plots. Certain traits such a total number of tillers, number of productive tillers, grain yield/plant, straw yield/plant, number of filled grains/panicle, plant height, panicle length, 1000 grain weight, spikelet fertility were observed in the weed free and the control plots. Significant difference was observedfor certain traits between the weed free and control plots. There was a vast reduction in the dry weight of the weeds in the herbicide sprayed plot when compared to the control plot. The weed control efficiency of the herbicide was found to range (Imazethapyr) from 74-92%.
T. C. Nikhitha, R. Pushpham, M. Raveendran and S. Manonmani
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
An experiment was performed to analyse the variability parameters and frequency distribution properties in F2population of CBMAS 14065 x Mappillai Samba for grain yield and its associated parameters. The estimated genetic parameters showed, slightly higher PCV than GCV reflecting the influence of environment. High GCV, high PCV, high heritability along with high genetic advance as per cent of mean was observed in the number of filled grains per panicle suggests the additive gene action which is important for selection. The parameters like plant height, the number of productive tillers per plant, panicle length, the number of filled grains per panicle and thousand grain weight showed a significant positive correlation with single plant yield. Significant positive skewness were observed for the number of productive tillers and grain L:B ratio which helps in fixing the selection criterias and benefits the improvement of traits in F2 generation.
M. A. Leon, K. Kumar, R. Pushpam, R. Kannan and M. Pillai
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
Genome engineering using Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR associated (Cas) system offers vast potential in the improvement of crop plants. For CRISPR/Cas9 mediated editing in rice, transformation protocols should be standardized for specific genotypes. We standardized the Agrobacterium-mediated transformation protocols for two genotypes – Improved White Ponni (IWP) and WP-22-2, a gamma-ray induced mutant of Improved White Ponni. Three different modifications of MS basal medium, different days old calli and bacterial culture of different optical density were evaluated. Callus induction with IWP-CI-medium-1 followed by callus proliferation for one month in IWP-CI-medium-2 produced transformable calli. Infection with 0.3 OD Agrobacterium culture for 10 min was less damaging and successful than higher density cultures. The transformation efficiency varied between the Improved White Ponni and WP-22-2 emphasizing the need for standardizing tissue culture protocols for every genotype. Transformation efficiency of 9.46 per cent and 3.53 per cent respectively were observed for Improved White Ponni and WP-22-2 which were higher than previous reports.
K. N. Ganesan, B. Meena Kumari, P. Veerabadhiran, Ashish K. Binodh, P. S. Devanand, R. Pushpam, D. Punitha, S. Maruthachalam, Sheela Venugopal, N. K. Prabakaran,et al.
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
The Spanish bunch groundnut variety BSR 2 is the cross derivative of VRI 2 x TVG 0004 It matures in 105 – 110 days. This culture is suitable for cultivation in rainfed and irrigated conditions. The culture BSG 0912 possess the advantage of bunch type growth with higher yield, more number of pods per plant, suitable for cultivation in all the groundnut growing districts of Tamil Nadu. The average yield of BSG 0912 under rainfed condition is 2222 kg/ha, which is 5.9, 18.3 and 19.1 per cent higher than VRI 8 (2099 kg/ha), CO 7 (1878 kg/ha) and VRI(Gn) 6 (1866 kg/ha) respectively. Under irrigated condition, this culture has the average yield of 2360 kg/ha with the yield increase of 15.5, 14.5 and 22.9 per cent over VRI 8 (2044 kg/ha), CO 7 (2061 kg/ha) and VRI(Gn) 6 (1920 kg/ha), respectively. The culture registered the shelling out turn of 70.2 per cent, oil content of 45.01 per cent and 100 Kernel weight of 41.0 g with preferable pod and kernel characters. The groundnut culture BSG 0912 possess moderate resistance to late leaf spot and rust diseases.
S. Robin, P. Jeyaprakash, K. Amudha, R. Pushpam, S. Rajeswari, S. Manonmani, V. Ravichandran, R. P. Soundararajan, A. Ramanathan, and K. Ganesamurthy
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
CR1009 Sub 1 a new version of long duration short bold grain rice variety CR1009 with submergence tolerance was released by Department of Rice, Tamil Nadu Agricultural University, Coimbatore, to overcome submergence during samba season for flood prone areas of Tamil Nadu. CR1009 Sub1 is a product of Marker Assisted Selection of the cross CR 1009/FR 13 A and it was developed by IRRI in collaboration with NRRI, Cuttack. CR1009 Sub1 rice variety recorded a mean grain yield of 5759 kg/ha with 8.90 per cent increase over CR1009. The variety was tested over three years in station trial (2008–2010), one year in Multi location trial (2010–11), two years in Adaptive research trial (2011–12 and 2012–13), two years in OFT (2010–11, & 2011–12) and one year in AICRIP trial (2010–11). CR1009 Sub1 is moderately resistant to BPH, WBPH, Brown spot and Leaf Blast. CR1009 Sub1 has short bold grain type with good milling percentage (69.8%) and head rice recovery (62.5%), high amylose content (25.0) intermediate gelatinization temperature and soft gel consistency indicating its similarity to CR1009 and also suitable for idly making. This variety was released by TNAU during 2015 and notified during 2017.
S. Robin, R. Pushpam, S. Rajeswari, K. Amudha, P. Jeyaprakash, S. Manonmani, M. Raveendran, R. Rabindran, A. Ramanathan, S. Suresh,et al.
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
In Department of Rice, Tamil Nadu Agricultural University, Coimbatore, a medium duration fine grain rice variety CO52 was released for cultivation in transplanted situation for late samba / thaladi season . CO52 rice variety recorded a mean grain yield of 6191 kg/ha and possessess quality grain traits comparable to the predominantly cultivated fine grain types. It is a derivative of the cross between BPT 5204 and CO(R) 50 which matures in 130-135 days. The variety was tested in the station trial for three (2009-2011)years, Multi Location Trial for two (2011-12 and 2012-13) years, Adaptive Research Trial for two (2013-14 and 2014-15) years, OFT for three (2013-14, 2014-15 and 2015-16) years and in AICRIP trial for two (2011 and 2015) years. CO52 variety is moderately resistant to insect pests viz., plant hoppers and leaf hoppers and diseases viz., blast, sheath rot, brown spot and sheath blight. It produces medium slender white rice with high milling percentage, high head rice recovery, high linear elongation ratio, intermediate amylose content, soft gel consistency and moderate gelatinization temperature indicating its suitability for cooking with a remunerative market price and consumer preference similar to Improved White Ponni and BPT 5204.
S. Robin, K. Mohanasundaram, S. Manonmani, S. Rajeswari, P. Jeyaprakash, R. Pushpam, K. Thiagarajan, R. Rabindran, S. Suresh, V. Ravichandran,et al.
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
Early duration rice culture CB 06 535, a derivative of the cross ADT 43 / RR 272 -1745 was released as TNAU Rice CO 51 during the year 2013 as an alternate variety to ADT 43 with 105 -110 days duration with additional desirable features like high yield, physiological efficiency and better adaptability. This culture with semi dwarf stature has efficient tillering capacity, long droopy panicles with highly acceptable plant characters and is a good replacement for the rice variety ADT 43 due to its high grain yield and pest and disease resistance. In the overall performance, the culture, CB 06 535 recorded a mean productivity of 6623 kg/ha in seven years of trials with 10.72 per cent increase over ADT 43. At Nallampalli, Dharmapuri district, the culture has recorded the highest yield of 11,377 kg/ha among the trials conducted, demonstrating the highest yield potential of this variety. The culture CB 06 535 is moderately resistant to blast, BPH and GLH under artificial condition. It produces medium slender white rice with intermediate amylose, soft gel consistency and moderate gelatinization temperature. It produces good quality cooked rice besides high milling and head rice recovery. CB 06 535 with higher yield, better pest and disease resistance and good cooking quality in comparison to the check ADT 43 is suitable for cultivation during Kar/ Kuruvai /Sornavari /Navarai and the seasons / tracts wherever early maturing rice varieties are cultivated throughout Tamil Nadu.
R. Pushpam, S. Nithya, S. Fathima Nasrin, E. Meena, K. Ramamoorthy, V. K. Parthiban, and M. Arumugam Pillai
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
Rice sheath rot has become a highly destructive rice disease with a high variability in yield loss levels varying from 20 to 85%. It is caused by many pathogenic agents varying depending on the area, grown varieties, prevailing environmental conditions, the farming system, other pests, etc. Therefore, sheath rot disease can be effectively managed through crop improvement strategies viz., discovery of resistance sources from varieties, germplasm, landraces, wild genetic resources and further deploying them in breeding programmes. In this study, the level of resistance to sheath rot in 43 rice germplasm accessions were screened and the results were grouped using Darwin 6.0 statistical package from dissimilarity analysis. The percent disease index (PDI) was calculated and varietal reactions were presented. Out of 43 lines screened against sheath rot, six entries viz., Gowri, NLR 3449, Navara, Soorakkuruvai, Keralakandasala, krishnahemavathi were categorised as moderately resistant. Most of the lines and varieties viz., JGL 348, Abhya, LFR293, MDU5, Kalinga, Annada, Kodaikannan, TP-100008, TP-10106, Kuruvaikalanjium, Kalyani, Maranella, Seeragasamba, Thondi, Kavara, TPS-4, TPS-5, TP 08053 were found as moderately susceptible. However, the germplasm lines Swarna, Kattanur, Dhalaheera and JGL 3855 have been reported to be resistant to sheath rot. Sixteen germplasm lines viz., Bharathi, Uma, CO 39, Neikuruvai, CO 50, Rajalakshmi, Karsamba, JGL 1798, CO 51, BPT 5204, Virendra, JGL 1798, CO 51, BPT 5204 and Aman were designated as susceptible and three germplasm lines viz., Athira, Malampunchan, Adukan were found as highly susceptible. None of the entry in the present study was recorded as immune. The present investigation revealed that the resistant and moderately resistant genotypes viz., Swarna, Kattanur, Dhalaheera, JGL 3855, Gowri, NLR3449, Navara, Soorakuruvai, Keralakandasala, and Krishnahemavathi can be utilised in resistant breeding programmes for the development of sheath rot resistant lines in rice.
R. Pushpam, S. Manonmani, N. Vishnu Varthini, and S. Robin
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
Plant selections with desirable root characters have been a major objective in breeding drought resistant variety of rice. Present study was therefore conducted to study the performance of rice varieties for yield, yield contributing characters, root characters and their association with drought tolerance. Drought resistant entries had recorded higher root thickness, root volume and deep root system than the susceptible genotypes. Correlation studies revealed that, all the characters showed positive and significant correlation with single plant yield. Drought score on the other hand exhibited significant negative correlation with yield. Spikelet fertility positively correlated with 1000 grain weight and yield but negatively correlated with drought score. Root depth was found positively correlated with root volume, root thickness, fresh weight of shoot and root and dry weight of shoot and root and exhibited significant negative correlation with drought score. This means that deep rooted varieties tend to be drought tolerant and have thick roots. Strong association between drought score and root thickness suggested that this character to be an important trait in identifying varieties for use in upland rice improvement for drought tolerance. Hence the characters to be given importance in selection are panicle/m, spikelet fertility and 1000 grain weight as they exhibited highly positive correlation with grain yield and also a positive inter-correlation among themselves. Selection based on root thickness and root depth is highly suitable for identifying varieties for use in upland rice improvement for drought tolerance.
P. Kanimozhi, R. Pushpam, Asish K. Binodh, R. Kannan, and M. Arumugam Pillai
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
The objective of present study is to identify promising TGMS lines with desirable floral and out crossing related traits for hybrid rice breeding. A total of seven new TGMS lines were raised during summer 2017 and observed under sterility favouring environment for tgms gene expression. Out of seven TGMS lines, four lines showed the stable performance and two TGMS lines viz., TNAU45S,TNAU60S were shown completely pollen sterile throughout the summer. Variability studies revealed that the characters viz., glume angle, stigma exertion percent and out-crossing per cent showing high GCV, Heritability and Genetic advance could be effectively utilized in selection. Correlation studies showed that the trait glume angle exhibited significant and positive correlation with extent of out crossing and spikelet sterility percent. The four TGMS lines viz., TNAU 39S, TNAU 45S, TNAU 60S, TNAU 95S registered the highest value for angle of glume opening (> 35%), panicle exertion percentage (> 90%) and stigma exertion percentage (> 65%). These lines had wider sterility expression period with very good floral traits viz., higher pollen sterility per cent, panicle and stigma exertion per cent, wider glume opening favorable for enhanced out-crossing rate and seed set percentage during seed production. From this study, the TGMS lines TNAU 39S, TNAU 45S, TNAU 60S and TNAU 95S were identified as promising based on floral and out crossing related traits and will be utilized for future hybrid breeding programmes towards the development of two line hybrids. Introduction Heterosis in rice was observed as early as in 1926 (Jones, 1926andRamaiah, 1933).However, attempts for the adaptation of hybrid technology were initiated only in 1966 by Yuan Long Ping, father of Hybrid rice, in China (Yuan, 1997). The identification of wild abortive (WA) type of cytoplasmic male sterility (CMS) in 1970 was a breakthrough in exploiting heterosis in rice breeding. Rice hybrids have a yield advantage of 15 to 20 per cent over the best conventionally bred varieties. China’s success in commercial hybrid rice production clearly demonstrates that hybrid rice is the most significant practical tool for increasing global rice production. Success in the use of hybrid rice technology depends on the extent of heterosis and efficiency of the seed production techniques. One of the major anticipated constraints to the sustenance of heterosis breeding in rice is the availability of quality seed within an affordable price range. There are two types of hybrid systems to develop hybrid rice. The first system is called a three-line hybrid, which is based on cytoplasmic genic male sterility (CGMS). The second system is called two line hybrid or environment-sensitive genic male sterility, (EGMS); these systems are controlled by nuclear gene expression, which is influenced by environmental factors (Virmani et al., 2003). The EGMS system using a two-line hybrid has a great number of advantages over the CMS system as the EGMS system is simpler and more effective due to the removal of the maintainer line from the three-line hybrid. EGMS genes are more easily transferred into almost any rice line. Moreover, the ratio of the cultivated area to EGMS line, seed production, and commercial production can be multiplied which reduces the hybrid rice seed cost and furthermore, the EGMS hybrid seed has a 5–10% greater yield than the CMS hybrid (Lopez and Virmani, 2000). In addition, there are no negative effects on the agronomic performance of the EGMS line itself and its resulting hybrids from male sterile cytoplasm and the critical temperature or photoperiod for inducing sterility should be as low as possible for greater stability of the EGMS lines with regard to seed production (Virmani et al., 2003). Material and Methods The seven TGMS lines viz., TNAU 39S, TNAU 45S, TNAU60S, TNAU 95S, TNAU 18S, TNAU 100S and TNAU 147S were raised during summer 2017 at Electronic Journal of Plant Breeding, 9(4): 1497-1502 (Dec 2018) ISSN 0975-928X 1498 DOI: 10.5958/0975-928X.2018.00185.0 Agricultural college and Research Institute, Killikulam. The materials were collected from Paddy breeding station, Tamil Nadu Agricultural University, Coimbatore. The temperature exceeds 32°C/24°C (day/night), pollen expressed as sterile condition and if the temperature is below 24°C/18°C (day/night), pollen becomes fertile condition. About 10-15 spikelets from the freshly emerged panicles of all the plants were collected and examined under microscope with the help of staining agent 1% Iodine Potassium Iodide (IKI) solution used to check the pollen sterility. Five elite plants in the middle row of each genotype from each replication were randomly selected to record the observations on days to fifty percent flowering, plant height, number of productive tillers per plant, panicle length, panicle exertion percentage, stigma exertion percentage, anther length, anther breadth, angle of glume opening, pollen sterility percentage, spikelet sterility percentage and extent of out crossing percentage. The mean data from each character individually was subjected to statistical analysis. Statistical analysis was done with the help of the package AGRES and GENRES. Mean data of genotypes for all characters was subjected to statistical procedure, ANOVA to separate the total variation in to different components and to test their significance (Panse and Sukhatme, 1995).Genetic parameters like GCV, PCV, heritability and genetic advance were calculated. Genotypic variance (GV) and phenotypic variance (PV) were computed according to the method suggested by Johnson et al. (1955).Genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were calculated using the formula suggested by Johnson et al. (1955).Categorization of the range of variation was effected as proposed by Sivasubramanian and Madhavamenon (1973).Genetic advance was estimated by the method given by Johnson et al. (1955).The association between floral characters and among themselves was computed based on genotypic and phenotypic correlation coefficients(Goulden,1952). Results and Discussion The first step in exploitation of two line rice hybrids is the identification of TGMS lines with stable sterility behavior. The major advantages of EGMS system are simplicity, overcoming the negative effects of male sterile cytoplasm, no need of maintainer line, less area required, less time and the seed multiplication is easy under restoration (Yuan, 1997). These two line hybrids have 5-10 % yield advantage over the three line hybrids. The observations recorded on the floral and morphological characters of TGMS lines are listed in Table 1. Out of seven TGMS lines, four lines showed the stable performance and two TGMS lines viz., TNAU45S,TNAU60S were completely pollen sterile throughout the summer period at Killikulam. These lines had complete pollen sterility under the high temperature. These lines could be utilized for two line hybrid rice breeding as they can be multiplied during winter month due to alternative temperature and hybrid seed production can be taken up during summer months. Similar results were reported by Thiyagarajan, 2010in their study with seven TGMS lines. The TGMS lines viz., TNAU39S, TNAU45S, TNAU60S, and TNAU95Sregistered the highest value for angle of glume opening (> 35%), panicle exertion percentage (> 90%) and stigma exertion percentage (> 65%). Among these lines, the trait of glume angle opening was varied from 22 ̊C to 37 ̊C. In the present study maximum glume angle opening was observed in TNAU45S (36.66 ̊) and minimum glume angle opening was observed in TNAU100S ( 22.17 ̊).Similar results were observed by Ravneet Behta et al., 2007 with the range of 23.43 ̊ to 30.20 ̊. The anther length ranges varied from 2.66 (TNAU 60S) to 1.89 mm (TNAU 18S). The general mean was 2.36 and two lines viz., TNAU 60S and TNAU 95S exceeded the general mean significantly. The range of anther breadth was from 0.56 mm (TNAU 39S) to 0.43 mm (TNAU147S). The general mean was 0.51 and none of the lines exceeded the general mean significantly. The range of panicle exertion percentage was from 95.87 (TNAU 45S) to 85.93 (TNAU 147S).The general mean was 91.12, and four lines exceeded the general mean significantly. The range observed for stigma exertion percent was varied from 43.13 (TNAU 18S) to 82.48 per cent (TNAU 60S). Spikelet sterility percent had a range of 93.43 (TNAU 147S) and 100.00 per cent (TNAU 45S, TNAU 60S). Three lines exceeded significantly over the general mean (96.77). The out crossing potential varied from 24.76 to 48.75 per cent. Minimum out crossing percent was obtained by TNAU18S (24.76) while the maximum out crossing per cent was recorded by TNAU 60S (48.75). Success of any plant breeding programme mainly depends upon the knowledge on genetic variability. The genotypic coefficient of variation measures the range of variability available in a crop and also enables to compare the amount of variability present among different characters. The phenotypic expression of the character is the result of interaction between genotype and environment. Heritability Electronic Journal of Plant Breeding, 9(4): 1497-1502 (Dec 2018) ISSN 0975-928X 1499 DOI: 10.5958/0975-928X.2018.00185.0 indicates the relative degree at which a character is transmitted from parent to offspring. High heritability values indicate that the characters under study are less influenced by environment in their expression and such characters could be improved by adopting simple selection methods. Furthermore, the information on genetic variation, heritability and genetic advance as per cent of mean helps to predict the genetic gain that could be obtained in later generations. The comparison of heritability values and expected genetic advance expressed as per cent of mean gives an idea about the nature of gene action governing a particular character. In the present investigation, the
M. Manjubala, R. Vasanthi, Patil Santosh Ganapati, and R. Pushpam
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
The assessment of stable genotypes to a wide range of environments is important for recommending cultivars in plant breeding programme. Therefore, twenty four genotypes of soybean were tested over three environments in Tamil Nadu. The stability analysis of GxE interaction observed data is mostly handled by parametric methods. If any assumptions of parametric methods are violated, the result of these methods may be questionable. The nonparametric measures are easy to analyse and simple to interpret which have more advantages than parametric methods. In this paper, nine nonparametric methods were used for identification of stable genotype and association among these measures were checked by correlation. According to Principle component analysis, nonparametric measures were divided into three groups Group 1 included Kang ranksum, NPi , NPi , NPi (3) and NPi , Group 2 included Si (3) and Si . Group 3 included Si (1) and Si . According to nonparametric measures, G17 is the stable one.
Vishnu Varthini Nachimuthu, R Pushpam, M Jyothsna, S Manonmani, M Raveendran, and S Robin
EJPB, ISPB, CPBG - Tamil Nadu Agricultural University
Drought, with its complex genetic nature possesses great challenge for resource deficient agriculture of this century. Even the climate change with its unpredictable weather pattern causes peak water scarcity. With these current challenges, genotypes with better root plasticity prove an effective way for sustainability in agriculture. Root, the ‘hidden half’ has high complexity for screening but serves as critical role for water and nutrient acquisition. Root phenomics was assessed by screening the RILs developed from Norungan and IR64 in modified transparent soil filled root box. RILs exhibiting extreme root phenome were screened under natural moisture stress condition in the field. Several candidate genes governing root development have been identified in rice. The genomic location of six candidate genes involved in root development pathway was obtained from OrygeneDB and specific microsatellites falling within and flanking these candidate genes were acquired from Gramene. Out of twenty-two microsatellites recovered and used for parental polymorphism survey, 3 microsatellites in the 3 candidate gene loci viz., OsMADS61, OsMADS23 and OsMADS27 exhibited polymorphism between IR 64 and Norungan. Association analysis of phenotypic and genotypic data indicated that all the three polymorphic markers significantly influenced the trait, maximum root length. The gene specific marker RM3558 (OsMADS61), and RM23170 (OsMADS23) also controlled the trait root volume, while the microsatellite marker, RM5789 linked to OsMADS27 had its influence on root: shoot ratio. This study identified significant candidate gene-linked microsatellites for utilization in drought tolerance breeding through marker assisted selection approach.