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The present research was conducted to examine different parameters of variability, correlations, and path coefficients associated with yield and yield-related traits in aerobic rice. The analysis of variance indicated noteworthy variations among the genotypes for all the traits investigated. Among them, flag leaf area and alkali spreading value showed high PCV and GCV. Except for days to fifty per cent flowering, days to maturity, and amylose content, the remaining traits demonstrated substantial heritability combined with high genetic advance as percentage of mean. The correlation analysis revealed significant positive association between grain yield per plant and several traits, namely effective tillers per plant, test weight, chlorophyll content, and length breadth ratio. Traits such as test weight, effective tillers per plant, and flag leaf area showed a positive direct effect on grain yield per plant. Therefore, it is crucial to give priority to traits that exhibit significant positive correlations and substantial direct effects during selection process. This approach will yield rewarding results in the development of high-yielding cultivars suitable for aerobic conditions. [ABSTRACT FROM AUTHOR]

A total of 50 genotypes were evaluated during Kharif 2022 in three different locations in Tamilnadu, India. The data on seed yield per plant was subjected to AMMI and GGE biplot analysis for stability study. The IPCA values explained 100% and 98.8% variation in AMMI and GGE biplot respectively. Results from both analyses inferred that the genotypes viz., Mash 114, Mash 1008, VBN (Bg) 4 and VBN 10 were stable across the environments with high mean seed yield per plant. Hence these varieties can be utilized for cultivation in varied environments of Tamilnadu. Besides, the genotypes; MASH 1008, MASH 114, VBN (Bg) 4, VBN 8, VBN 10 and VBN 11 were found to be resistant to MYMV based on the field screening at National Pulses Research Centre, Vamban, Pudukkottai. [ABSTRACT FROM AUTHOR]

The present study explicates the genetics of 15 (eight yield traits and seven quality traits) basmati traits by employing generation mean analysis in six crosses of basmati rice crosses. Generation mean analysis is a biometrical tool which not only can identify presence of epistasis but also explain its types and role in inheritance of traits. Simple and Joint scaling test indicated role of epistasis in inheritance all the six crosses except for alkali spread value in the cross HUBR10-9 x PuB-1509, which showed dominance gene action. 90 individual tests each of simple and joint scaling tests divulged role of one or the other type of epistasis in inheritance of different traits in all the six crosses except for alkali spread value in cross HUBR10-9 x PuB-1509, which showed dominance gene action. Complementary digenic interaction were observed for yield per plant trait; however, other traits showed equal importance of complementary and duplicate digenic interaction in inheritance of different traits examined in the present study. Most of the traits were governed by epistatic gene action which suggested that traits of such population can be improved when the selection process is delayed. However, selection can be practiced at early stage of breeding program in such traits which were governed by additive gene action. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa L.), a semi-aquatic crop cultivated in diverse environments from sea coasts to high altitudes, faces submergence issues impacting one-third of global cultivation. Effectively choosing superior offspring with a range of genetic traits is vital for improving yield stability, particularly in the development of submergence-tolerant varieties. This is accomplished by comprehending gene action through the generation mean analysis. This experimental material comprised six generations (P1, P2, F1, F2, B1, and B2) obtained from two rice crosses viz., ADT 45 x APD 19002 and CO 54 x APD 19002 involving three parents, examining twelve traits. In the cross ADT 45 x APD 19002, traits like days to fifty per cent flowering, plant height, number of productive tillers per plant, flag leaf width, total number of grains per panicle, number of filled grains per panicle, and single plant yield exhibited opposite signs of dominance (h) and dominance x dominance (l), indicating a prevalence of duplicate epistasis. Simultaneously, additive(d) and additive x additive(i) gene effects were displayed by days to fifty per cent flowering, total number of tillers per plant, panicle length, flag leaf width, total number of grains per panicle, and single plant yield. In cross CO 54 x APD 19002, traits such as days to fifty per cent flowering, plant height, flag leaf width, number of filled grains per panicle, spikelet fertility, and single plant yield suggested predominance of duplicate epistasis. Meanwhile, additive and additive x additive gene effects predominantly influenced the days to fifty per cent flowering, spikelet fertility, and single plant yield. These findings propose the potential for improvement through later-generation selection, emphasizing the integration of selection with screening for submergence tolerance to develop high-yielding submergence-tolerant varieties. [ABSTRACT FROM AUTHOR]

A half-diallel cross involving nine diverse brinjal genotypes, excluding reciprocals, yielded thirty-six combinations for the investigation of combining ability and gene action related to yield components. Varied genetic differences were observed among the genotypes for analyzed features, indicating that both additive and non-additive gene actions are influencing most traits. Examination of the overall combining ability effects highlighted JBR-5, JBR-3, and JBR-4 as effective general combiners for both fruit yield per plant and fruit and shoot borer infestation. Crosses demonstrating substantial specific combining ability effects in fruit yield also displayed noteworthy impacts on one or more components of yield. Promising combinations like JBR-3 X JBR-5, JBL-1 X JBR-5, and JBL-2 X JBL-3 showed potential for varietal improvement, pending multi-location yield trials to confirm their effectiveness. The most favourable cross, JBR-3 X JBR-5 (0.60), demonstrated significantly positive SCA effects for yield per plant, coupled with high and positive effects for fruit length and number of fruits per plant. Further, it also demonstrated enhanced fruit and shoot borer resistance. Most traits exhibited high narrow-sense heritability, suggesting a predominant role of additivity in phenotypic variability. Understanding the genetic mechanisms influencing economically important quantitative traits is crucial for devising successful breeding strategies. Future research should delve into advanced genomic techniques to unravel the genetic architecture of these traits and expedite the development of improved brinjal varieties with enhanced yield and resistance characteristics. [ABSTRACT FROM AUTHOR]

Two sets of 28 interspecific HxB hybrids generated in LxT fashion, along with their parents were evaluated for 11 yield and fibre quality parameters. GCA variances were lower than SCA variances for all the characters in both sets, as indicated by their lower ratios suggesting predominance of non-additive gene action. Based on both per se and gca effects, GJHV 374 BT, RAJAT BT, ICB 39 and CCB 141 in Set I and GJHV 374 BT, SURAJ BT, ICB 176 and SUVIN in Set II were found to be the best parents which could be utilized for the hybridization programme to obtain superior segregants with yield and fibre qualities. The hybrids viz., RAJAT BTxICB 99, RAJAT BTxICB 34,SURAJ BTxICB 39, GJHV 374 BTxICB 264, SURAJ BTxICB 264 and SURAJ BTxICB 284 showed significant sca effects. Hence, it may be concluded that the above hybrids are the best specific combiners for different yield-contributing and fibre-quality traits. The sca effect was found to be positive in17 crosses and 11 crosses for single plant yield in set I and II, respectively. Similarly, six crosses each in sets I and II were found with a positive sca effect for fibre length. [ABSTRACT FROM AUTHOR]

An experiment was carried out during Kharif 2020 at wetland farm of Sri Venkateswara Agricultural College, Tirupati using 30 inbred lines of maize to assess the trait association for 16 yield and yield attributes. It revealed that ear length, number of kernels per row, plant height, ear girth, SPAD chlorophyll meter reading, 100 kernel weight, number of kernel rows per ear, specific leaf area, harvest index and tassel length had notable positive correlation with kernel yield per plant suggesting that selecting these characters simultaneously lead to an increase in kernel yield per plant. Path analysis revealed a significant and positive direct influence of ear length on the kernel yield per plant. Hence, ear length could be considered during selection in maize for improving kernel yield. [ABSTRACT FROM AUTHOR]

Sixty different varieties of brinjal (Solanum melongena L.) were evaluated for character association. The findings showed that the genotypic correlation was higher than the phenotypic correlation coefficient for most traits. Strong positive correlation was observed between the number of fruits per plant, branches per plant, and fruit yield per plant. Positive correlation was observed between moisture content and fruit characteristics, such as fruit volume and average fruit weight. The path coefficient analysis revealed that high positive direct effect on fruit yield was exerted by fruits per plant, followed by moisture content. [ABSTRACT FROM AUTHOR]

The current study involved the evaluation of 96 pearl millet hybrids synthesized by crossing eight lines with 12 testers using a Line x Tester mating design. The experiment was conducted during the Kharif season of 2022 with two replications and included standard checks COH10 and 86M38. Analysis of variance for combining ability revealed that, significant amount of variation was present in all hybrids for studied traits. The contribution of lines to the total variance in hybrid was greater than tester. The ratio between GCA and SCA variance was less than one for all traits and it showed that non additive gene action was predominant and highlighting the potential of heterosis breeding to exploit hybrid vigor. Among the parents, ICMB 02777 and PT 6679 were identified as good combiners, showing positive gca effects and high mean performance for grain yield, test weight, single earhead weight, and single earhead threshed weight. The other parents viz., ICMB 02444, ICMB 93222, PT 6067, and PT 6476 were also recognized as good combiners for grain yield. Out of the 96 hybrids, the cross ICMB 02777 x PT 6679 exhibited significant positive heterosis along with high standard heterosis over both checks for grain yield, test weight and single earhead threshed weight. Additionally, the crosses ICMB 02444 x PT 6679, ICMB 93222 x PT 6067 also recorded significant sca effect for grain yield per plant. These promising hybrid combinations hold great potential for heterosis breeding programs and may be suitable for commercial exploitation after thorough evaluation under multi-location trials. [ABSTRACT FROM AUTHOR]

A study was carried out to assess character association and genetic diversity among green gram genotypes. The results of correlation coefficient analysis revealed a significantly positive correlation for the traits viz., plant height, number of primary branches, number of clusters per plant, pod length, and number of seeds per pod with single plant yield. The path analysis revealed that the number of pods per plant, number of seeds per pod, and hundred seed weight had the highest positive direct contribution to single plant yield. Pod length showed a low indirect contribution to the total variance and all other traits showed a negative contribution to total variance. [ABSTRACT FROM AUTHOR]

A study was conducted to analyze the interaction of twelve maize genotypes with the environment for fourteen traits. The crop was grown during the kharif season of 2021 and 2022 in six different environments using two production systems, natural farming and the inorganic production system, in Palampur and Kangra using randomized block design with three replications. G × E interaction and stability analysis following AMMI model exhibited significant variation due to genotypes and environments for all the traits, indicating the presence of sufficient variability among the genotypes and environments. In contrast, G × E interaction was significant for all the traits except for number of kernel rows per cob and ear circumference (cm). Results showed that significant variation was present among the genotypes and environments. The environment had greater impact on most traits, except number of kernel rows per cob, ear circumference (cm), 100- grain weight (g), harvest index (%) and protein (%).The mean squares for the IPCA 1, IPCA 2 and IPCA 3 cumulatively contributed more than 80% of the total G × E interaction for all the traits. Overall,Girija was found to be the most stable genotype for the maximum number of traits, followed by L-315 and L-316.Girija was most stable for grain yield per plant followed by L-315, L-316 and L-318 under the inorganic production system. Bajaura Makka followed by L-315 and L-316 were stable genotypes under the natural farming production system with high grain yield per plant. Both L-315 and L-316 were found to be suitable for cultivation under both farming methods. [ABSTRACT FROM AUTHOR]

In the present study, genetic diversity was assessed in RIL population developed at Indian Institute of Soybean Research (IISR) Indore by crossing of released varieties JS 97-52 and NRC 37. The Analysis of variance suggested that all the studied traits differed significantly. High heritability with high genetic advance as percent of mean was observed for plant height, number of primary branches, number of pods/plants, number of seeds/plants, days to maturity, biological yield, 100 seed weight, harvest index and seed yield per plant. Significant positive association with grain yield per plant was observed for days to 50% flowering, days to maturity, plant height, number of primary branches per plant, number of pods per plant, number of seeds per plant, biological yield per plant, harvest index and 100 seed weight. The highest positive direct effect towards grain yield was exerted by biological yield per plant, followed by harvest index and number of pods per plant. Diversity analysis revealed that Cluster VI and XII had highest inter cluster distance. [ABSTRACT FROM AUTHOR]

Thirty-four red kernel rice genotypes along with two check varieties were evaluated across three different locations of Tamil Nadu viz., Coimbatore, Paiyur and Aduthurai during Kharif 2022 to assess the stability of the genotypes for single plant yield. The AMMI and GGE models were used to study the interaction between the genotypes and the environment in order to select the stable genotypes. Significant differences among the genotypes and the environment revealed the existence of variations among the genotypes and also environmental influence over the genotypes for single plant yield. Considering the overall average single plant yield performances, the genotype Rangoon samba recorded the highest single plant yield over the check varieties, while the genotype Karuthakar had the lowest single plant yield. The genotypes G24 (Thooyala), G25 (Kothamalli samba) and G34 (IG74 Check) recorded higher stable single plant yield across locations. Based on AMMI and GGE stability models, these three genotypes were identified to be highly stable over environments with less G x E interaction and these genotypes can be recommended for cultivation across the environments to obtain a higher single plant yield. [ABSTRACT FROM AUTHOR]

Hybrids show better performance than varieties in terms of yield and quality. Heterosis breeding provides a way to develop hybrids to uplift yield and quality. In the current study, 21 hybrids generated through line × tester mating design were evaluated along with the standard check, Arka Rakshak, in a randomized block design to investigate the magnitude of standard heterosis. Significant difference was observed among the genotypes pertaining to days to 50% flowering, plant height (cm), fruits per plant, fruit weight (g), fruit girth (cm) and seeds per fruit. Estimation of standard heterosis in desirable direction was identified for all characters. NTL-14-08 × DVRT-2, NTL-14-08 × GT-6 and NTL-14- 08 × GT-7 are the top three crosses that showed higher positive standard heterosis for fruit yield per plant (kg). The heterotic response in hybrids for different characters is in general agreement with the per se performance of hybrids. Phenotypic correlation study indicated that the number of fruits per plant is positively correlated with fruit yield per plant and negatively correlated with days to 50% flowering with significance. [ABSTRACT FROM AUTHOR]

Fourty-eight ashwagandha [Withania somnifera (L.) Dunal] genotypes were studied for the genetic variability, heritability and trait association during 2018-19 based on 13 yield and quality traits. For all the 13 characters studied, highly significant (P < 0.01) differences were observed. Parameters such as withanolides, dry root yield per plant and crude fibre recorded higher estimates for GCV and PCV. High broad sense heritability and genetic advance were recorded for number of primary and secondary branches, number of berries, root length, number of secondary roots, fresh and dry root yield, starch, crude fibre and withanolides. These proved to be promising traits that would respond to selection of better genotypes owing to their high transmissibility and genetic variability. Character association study indicated that dry root yield had positive and significant association with the number of primary and secondary roots, fresh root yield and withanolides at both genotypic and phenotypic levels. Path analysis revealed that number of secondary roots and withanolides were major traits having high positive, direct effect and significant association with dry root yield. Hence, these traits would be quite effective when selected to improve dry root yield in ashwagandha. [ABSTRACT FROM AUTHOR]

The aim of the present study was to assess the degree of genetic variation, heritability, and character relationship among yield, yield attributing and grain quality parameters in BC3 F2 of CO 52 x APD19002 population. In the current study, number of total tillers per plant, number of productive tillers per plant, flag leaf length, number of filled grains per panicle and single plant yield showed high PCV and GCV. It became evident that there exists a highly significant and positive association between single plant yield and number of productive tillers per plant followed by number of tillers, flag leaf length, plant height, spikelet fertility and test weight. The path coefficient analysis showed that number of productive tillers per plant had high positive direct effect on single plant yield followed by flag leaf length, kernel length, KBAC and LER. The results indicate the number of productive tillers per plant and flag leaf length were identified as the key contributing traits as they are highly heritable and simultaneous consideration of these traits is important for crop improvement. It implies that flag leaf provides more photosynthates to grains along with number of productive tillers per plant which in turn increases the grain yield. [ABSTRACT FROM AUTHOR]

The current study was conducted to determine the genetic diversity present among the popular varieties and advanced cultures of groundnut. Genotypic correlation between single plant yield with number of pegs/plant and number of pods/plant was significant and positive. High heritability along with high genetic advance as a percentage of mean was found for plant height, no. of branches/plant, no. of pegs/plant, no. of pods/plant, hundred kernel weight and pod yield/plant. The 46 genotypes were grouped into five clusters based on D² analysis. The highest intra-cluster distance was recorded for cluster VI followed by clusters II, I, III and V. Maximum inter-cluster distance was observed between clusters IV and V followed by clusters II and V. Minimum inter-cluster distance was observed between clusters I and II. PCA was used to estimate the relative contribution of various traits to the total variability. Three components (PC1, PC2 and PC3) were found to have more than one eigenvalue and they accounted for 67.23 per cent of the variability of the genotypes used. [ABSTRACT FROM AUTHOR]

Proso millet, being the climate-resilient crop among cereals can be grown for food and fodder purposes. The current study was carried out to assess the variability, association, and divergence for 15 biometrical traits among 72 Proso millet accessions. The traits viz., number of basal tillers, flag leaf blade width, peduncle length, number of grains per panicle, dry fodder yield and single plant yield contributed maximum for the variability among the genotypes. High heritability with high genetic advance were recorded for the traits namely plant height, number of basal tillers, flag leaf blade length, flag leaf blade width, peduncle length, panicle length, number of grains per panicle, number of primary inflorescence branches, crude protein, dry fodder yield and single plant yield. Therefore selection based on these traits will be rewarding in future proso millet breeding programs. The traits such as plant height, number of basal tillers, flag leaf blade width, peduncle length, number of grains per panicle, and number of primary inflorescence branches were positively and significantly correlated with single plant yield, indicating the importance of these traits while improving the yield. High positive direct effect in path coefficient analysis for the traits plant height, flag leaf sheath length, panicle length, peduncle length, and thousand-grain weight indicated that yield improvement can be accomplished by direct selection based on these characters. Divergence by using Mehalanobis D2 analysis resulted in ten clusters. High inter cluster distance was observed between the clusters VII and X, VI and X, VI and X, and XII and I. Therefore, hybridization between the genotypes among the respective pair of clusters would be desirable to have high heterotic crosses. [ABSTRACT FROM AUTHOR]

Maize is one of the important cereals in the world. It is a good source of carbohydrates (70-87%) and protein (6-13%). To develop a high-yielding variety of any crop, heritability and genetic advance are important selection parameters for the selection of yield and yield attributes. In this regard, the present investigation was carried out at the Namdeo Umaji Agri Tech India Private Limited, Pune, during Kharif, 2022 to study the extent of variability among maize genotypes. Observations were recorded on 19 polygenic traits and the mean values were subjected to statistical analyses. High GCV and PCV were recorded for anthesis and silking interval, number of leaves, lodging percentage, number of kernels per row and grain yield per plant. High heritability accompanied by high genetic advance was noted for anthesis and silking interval, lodging percentage, grain yield per plant, number of leaves per plant, number of kernels per row, number of tassel branches, leaf width, days to 50% silking, protein content, leaf length, number of kernel rows per cob, cob diameter and cob length. It indicates that these traits are governed by additive gene action and selection will be rewarding for improving these traits in maize. [ABSTRACT FROM AUTHOR]

Sorghum (Sorghum bicolor L. Moench) is a significant crop known for its resilience, versatility, and nutritional value. The research aimed to enhance yield and nutritional quality through the assessment of genetic variability, heritability, correlations, and causal relationships among traits. Variance component analysis in the F2 population of red sorghum genotypes from the cross between Paiyur 2 and IS 21731 revealed the influence of the environment on trait expression. High variability in flag leaf traits and single plant yield was observed. Traits such as plant height, stem girth, and flag leaf length exhibited high heritability and genetic advancement which indicated that these traits are influenced by additive genetic factors and are suitable for selection processes. Positive correlations were identified between single plant yield and traits like panicle weight and primary branches and hence selection based on these characteristics could directly contribute to improved yield in sorghum. Path analysis highlighted the direct and indirect effects of traits on grain yield with panicle weight emerging as a major driver. This study provided valuable insights into effective breeding strategies emphasizing traits such as panicle weight, primary branches, and seed index for enhancing both yield and nutritional quality in red sorghum genotypes. [ABSTRACT FROM AUTHOR]

Sunflower production can be increased by exploring genetic variability present in the population. The nature of relationship between yield and its associated traits should be clearly understood to achieve parallel improvement of yield by indirect selection of beneficial traits. In the present study, 50 sunflower accessions along with five checks were evaluated for nine biometrical traits viz. days to 50% flowering, days to maturity, plant height, head diameter, hundred seed weight, volume weight, hull content, oil content and single plant yield to assess the variability and character association. The analysis of variance revealed the presence of significant variation among the genotypes for all the traits under consideration. Phenotypic coefficient of variation and genotypic coefficient of variation values were high for hundred seed weight and single plant yield. High heritability along with high genetic advance was observed for the traits viz. days to 50% flowering, plant height, head diameter, volume weight, oil content, hundred seed weight and single plant yield. Correlation studies revealed the presence of a positive and significant correlation between single plant yield and the traits head diameter and hundred seed weight. Similarly, oil content exhibited a positive and significant correlation with head diameter and volume weight. Path analysis also indicated the presence of high and moderate positive direct effect of head diameter and hundred seed weight on single plant yield. Based on the above, head diameter and hundred seed weight could be used as selection indices for yield improvement in sunflower. [ABSTRACT FROM AUTHOR]

The present study aims to evaluate the genetic variability, character association and path coefficient for various quantitative traits in fifty rice genotypes comprising of landraces and varieties under water limited conditions. Drought being a major abiotic stress causes severe reduction in grain yield especially during reproductive stages. The results revealed the presence of high genetic variability and significance for all the traits studied. The traits like single plant yield, number of filled spikelets per panicle, number of productive tillers per plant, flag leaf length, leaf rolling and leaf drying showed high variability compared to all other traits. The traits viz., spikelet fertility, number of productive tillers per plant, number of total tillers per plant, plant height, flag leaf breadth, panicle length, number of filled spikelets per panicle and relative water content exhibited a significant and positive correlation and direct effect on single plant yield, suggesting the potential importance of these traits in the improvement and selection of stable and high-yielding rice genotypes. [ABSTRACT FROM AUTHOR]

Soybean is an important legume cum oil seed crop of the country. Generation of information on genetic control of traits and association among them could play a great role in targeted crop improvement. In this study, 76 soybean genotypes including five checks were characterized and evaluated during summer, 2023. The traits namely plant height, number of branches per plant, number of pods per plant, number of clusters per plant and single plant yield showed high GCV and PCV. High heritability and GAM were also observed for the above traits. Traits namely the number of pods per plant, number of branches per plant, number of clusters per plant, number pods per cluster, number of seeds per pod and plant height had significant correlation with yield and direct effects observed to be higher for number of pods per plant and plant height. This study suggested that selection for number of pods per plant, number of branches per plant and number of clusters per plant could be useful to improve the yield and evolve high yielding varieties. [ABSTRACT FROM AUTHOR]

The evaluation encompassed 52 sesame germplasms to assess their variability and diversity. Number of primary branches, number of capsules per plant and single plant yield were the traits having high PCV and GCV along with high heritability and genetic advance as percent of mean. These findings suggest considerable variation for these traits among the germplasms and are strongly influenced by genetic factors, making them suitable candidates for effective selection strategies. The diversity among 52 sesame germplasm accessions were analysed using Mahalanobis D2 analysis andAgglomerative hierarchical clustering. They were grouped in to 11 clusters using Mahalanobis D2 analysis. Cluster II was the largest, followed by cluster I. Highest intra-cluster distance was observed for cluster VIII, followed by cluster IV and cluster II. The greatest inter-cluster distance was observed among cluster VI and VII. Agglomerative hierarchical clustering (AHC) based on Ward’s method was used to group the accessions, into clusters of increasing dissimilarity. The highest dissimilarity was observed between the genotypes CO1 and VRI-NIC-16381. Based on the AHC and D2 analyses, genotypes with moderate to highest mean values from distant clusters are recommended as parental candidates in crop improvement programs to facilitate the creation of superior cross combinations. [ABSTRACT FROM AUTHOR]

Drought is an important factor limiting rice productivity in rainfed ecosystem. Development of high yielding drought tolerant rice varieties would increase rice production under such condition. In the present study, 116 qDTY QTL introgressed back crossed inbred lines (BILs) derived from the crosses viz., ADT (R) 45 * 3/Apo, ADT (R) 45 * 3/ Way Rarem and ADT (R) 45 * 2/Apo // ADT (R) 45 * 2/ Way Rarem along with parents were evaluated to assess their performance under target production environment. Estimates on genetic variability, trait association, direct and indirect effects of yield and yield components and principal component analysis were worked out. The results of genetic variability showed wide variation among the genotypes for different traits. High values of PCV than GCV showed the influence of environment on the traits. Genotypes could be selected based on total number of tillers per plant, number of productive tillers per plant, spikelet fertility, single plant yield, 1000 seed weight and grain yield per plot, which were found to have high heritability and genetic advance. Correlation analysis exhibited high and significant positive correlation of grain yield per plot with single plant yield and non significant positive association of all the traits except plant height that was negatively correlated. Path coefficient analysis of the genotypes showed that total number of tillers per plant had maximum direct effect on grain yield, while number of productive tillers per plant had high indirect effect on grain yield via total number of tillers. Based on genetic variability, correlation and path analysis, selection for six traits, viz., total number of tillers per plant, number of productive tillers per plant, single plant yield, spikelet fertility, 1000 seed weight and grain yield per plot, would be rewarding. The results of principal component analysis revealed that, four out of eleven principal components viz., PC1, PC2, PC3 and PC4 contributed 72.62% of the total variation with eigen values more than 1. PC1 accounted for the highest variability with 24.66% followed by PC2 (20.42%), PC3 (16.19%) and PC4 (11.35%). From this study, the traits contributing for variation were identified and the resulting genotypes would be beneficial for improving yield with drought tolerance. [ABSTRACT FROM AUTHOR]

The present investigation was undertaken in 110 mung bean genotypes in alpha lattice design in two replications to estimate the correlation coefficients, direct and indirect effects of various yield contributing traits on grain yield for 18 quantitative traits and nine screening traits against bruchids. The correlation coefficient analysis revealed that single plant yield showed high significant positive correlation with number of pods per plant, followed by number of clusters per plant and hundred seed weight. Path analysis showed that days to 50 per cent flowering and number of pods per plant showed high positive direct effect on single plant yield. The bruchid bioassay resulted in the identification of 12 genotypes with complete resistance to bruchids and all the characters showed high significant positive correlation with each other except for number of eggs laid. Hence, the resistant genotypes identified in this study can be used in resistance breeding programme for bruchids. [ABSTRACT FROM AUTHOR]

The present experiment was undertaken to study the variability, trait association and principle component analysis among eighteen characters in 53 rice genotypes including landraces and cultivars. Higher estimates of GCV and PCV coupled with high heritability and GAM were observed for a number of filled grains per panicle followed by a number of spikelets per panicle and single plant yield indicated that these traits could be utilised for selection in rice improvement. Study of association of yield attributing traits revealed that the single plant yield had a significant positive association with the total number of spikelets per plant, number of filled grains per plant and number of primary branches per plant and had a significant negative association with the length of the primary branches. Hence, direct selection of positively associated characters can improve the grain yield and increased primary branch length reduces the number of primary and secondary branches that might lead to a reduction in yield. Path coefficient analysis showed that the number of spikelets per panicle, primary branches per plant and length of secondary branches had a positive direct effect on yield. Therefore, giving weightage during selection to the above the mentioned traits could improve the yield and yield attributes. The principal component analysis showed that out of 18 traits studied, only eight principal components (PCs) had Eigen values greater than 1.00 and accounted for approximately 80.18% of the total cumulative variability. Single plant yield, number of fertile spikelets and total number of spikelets per plant and number of tillers showed maximum vector length confirming that the maximum contribution to the total diversity and the genotypes with the above characters could be utilized as donors to improve the yield and its attributing traits in future breeding programme. [ABSTRACT FROM AUTHOR]

Groundnut is the third-largest oilseed crop produced in the world and second largest in India. The F2 populations of TMV 7 x Girnar 4 and R2001-2 x Girnar 4 were evaluated to determine the variability and association between yield and its attributing traits. High PCV and GCV along with high heritability and genetic advance as percent of mean were observed for the trait viz., primary branches, secondary branches, number of pods, immature pods, mature pods and pod yield . Improvement of these traits would be possible through simple selection program as they are controlled by additive gene action. The traits number of pods, mature pods, 100 kernel weight and shelling percentage showed significant positive correlation with pod yield in both the crosses. The path analysis results revealed that the number of pods per plant had the highest positive direct effect on pod yield per plant and the selection for these traits could positively increase pod yield/ plant. [ABSTRACT FROM AUTHOR]

Five sorghum (Sorghum bicolor (L.) genotypes were crossed in a half-diallel mating design. Analysis of variance for combining ability revealed that general combining ability (GCA) was significant for all the traits except days to flowering, while specific combining ability was significant for all the studied traits. The variance ratio (δ²GCA / δ²SCA) was less than unity for all characteristics, demonstrating the role of non-additive gene action in controlling yield and component traits. The result of general combining ability (GCA) indicated that the parents SH 1488 and SH 1813 were as good general combiners for both green and dry fodder yield per plant. Result of specific combining ability (SCA) showed that crosses SSG 59 × SH 1488, SH 1488 × SH 1813, SH 1488 × S 652 and SH 1811 × S 652 recorded the highest sca effect for the traits green and dry fodder yield per plant. The t² test specified the fulfilment of the assumption required under diallel analysis for all studied traits except leaf length (cm) and green fodder yield per plant (g). Non-significant result of t² value suggested additive dominance model for all the traits except leaf length (cm) and green fodder yield per plant (g). The higher value of H1 compared to H2 for most of the characters suggested that gene sharing frequency in parent genotypes was not equal and that was also supported by the H2 / 4H1   (<0.25). The greater than one value of KD/KR components for most of the traits except leaf width (cm) and HCN content (ppm) suggested the higher frequency of dominant genes than recessive genes in the parents. The estimation of the F component was positive and non-significant for all the traits except leaf width (cm), whose value was negative. In Hayman's graphical analysis, the regression line interrupted Wr axis below the origin suggested over dominance for days to flowering, leaf: stem ratio, number of leaves per plant, stem girth and Brix content. [ABSTRACT FROM AUTHOR]

A study was carried out to understand the genetic variability and trait association in a set of 30 naturally coloured cotton hybrids along with their parents (five colour cotton and six white cotton parents). The Analysis of Variance revealed the significance of the mean square for most of the traits studied. The phenotypic coefficient of variation was more than that of the genotypic coefficient of variation for all the traits. High PCV and GCV were recorded for the traits number of monopodia and single plant yield. The heritability and genetic advance as percentage of mean (GAM) were high for the traits plant height, number of monopodia, number of bolls per plant, single boll weight, bundle strength, fibre fineness and single plant yield. The Number of sympodia, number of bolls per plant and boll weight were observed to have significant genotypic and phenotypic correlation with single plant yield, while upper half mean length was observed to have significant genotypic and phenotypic correlation with bundle strength and fibreelongation. Path analysis revealed that seed index and ginning out turn recorded very high direct effect with single plant yield. [ABSTRACT FROM AUTHOR]

In this study, the genetic diversity among forty-two rice genotypes were evaluated for fifteen quantitative and eleven qualitative traits using D2 statistics and DUS characterization. The genotypes were grouped into eight clusters of which the cluster VIII was the largest consisting of twelve genotypes. While, the clusters IV and VII were the smallest with a single genotype each. The maximum inter-cluster distance was observed between clusters I and II. Hence, the genotypes from these clusters could be used as parents for rice hybridization programmes in future. Among all traits, days to 50% flowering and apiculus colour were found to be the major contributing quantitative and qualitative traits towards genetic diversity. Beyond this, in this study Cluster II recorded the highest mean value for shoot length, plant height, flag leaf width, panicle length, number of seeds per panicle, 1000 grain weight and single plant yield. However, the cluster VII recorded the highest mean for seedling height, flag leaf length, grain length and grain width. Thus, the genotypes from these clusters which were Aanai Komban, Kichili samba and Karuppu kavuni could be used in improving the yield parameters in rice. Further, the correlation analysis for fifteen traits revealed a significant positive correlation of number of productive tillers, flag leaf length, flag leaf width, number of seeds per panicle, grain length and 1000 grain weight with single plant yield. Further the path analysis portrayed that the from these correlated traits, number of productive tillers, flag leaf width, number of seeds per panicle and grain length were observed to have a positive direct influence on yield. Thereby, it could be observed that these traits could be used as major indicators for selection of desirable genotypes for utilization in hybridization programme to develop elite rice genotypes. [ABSTRACT FROM AUTHOR]

This study aimed to assess the genetic variability, heritability, genetic gain and trait relationships of sixteen biometrical characteristics in a collection of eighty-nine rice cultivars, landraces and exotic lines. The focus was on understanding the degree of genetic divergence and identifying traits with high selection potential. The analysis revealed that economic yield improving traits like single plant yield, filled grains per panicle and total number of productive tillers showed high GCV, PCV, heritability and genetic gain implying the predominance of additive gene action and these traits can be given importance in selection and genetic advancement for yield improvement. Days to 50% flowering, plant height, total number of productive tillers, filled grains per panicle and thousand grain weight showed notable significant associations with single plant yield, with direct effects, asserting that these traits were most efficient and promising for selection. Cluster analysis revealed two clusters with cluster 1 mostly occupied by elite cultivars and cluster 2 occupied mostly by landraces and exotic lines. This information can be valuable for further studies and breeding programs, allowing researchers to focus on specific clusters for targeted genetic improvement or conservation efforts. [ABSTRACT FROM AUTHOR]

The present study was focused on evaluating the F3 population of VBN 11 x LBG 17 based on 10 yield components and the per cent disease index (PDI) for powdery mildew. Variability, correlation, and path analyses were performed to examine the data. The F3 population exhibited a wide range of variation for both yield components and PDI. Notably, the number of branches per plant, PDI, and seed yield per plant (g) showed high phenotypic and genotypic coefficients of variation. Furthermore, PDI alone displayed high heritability along with a high genetic advance as a percentage of mean. Moderate heritability and high genetic advance as a percentage of mean were observed for plant height (cm), number of branches per plant, total number of pods per plant, and seed yield per plant (g). These findings suggest that these traits are influenced by additive gene action and are suitable for effective selection. Correlation analysis revealed that all traits, except PDI and 100-seed weight, were significantly associated with seed yield per plant (g). Path analysis indicated that the total number of pods per plant had a substantial direct effect. Consequently, the total number of pods per plant can serve as a selection index for yield improvement programs. Notably, PDI exhibited no association with seed yield per plant (g), suggesting that resistant genotypes can be developed without any adverse correlation among yield components. [ABSTRACT FROM AUTHOR]

The present investigation was undertaken in 48 desi cotton genotypes to study the genetic divergence and character association for fibre quality and yield related traits. The results of Mahalanobis D2 analysis indicated the presence of considerable genetic divergence among the genotypes. They were grouped into nine clusters. The crosses made between the genotypes of cluster V (NDLA-3066) with cluster VII (NDLA 3105-5) followed by cluster IX (NDLA 3147- 2) with cluster VII (NDLA 3105-5) and cluster VI (NDLA-2974) with cluster VII (NDLA 3105-5) are expected to give desirable segregants. Of the 15 characters studied, elongation percentage, seed cotton yield, UHML, bundle strength and lint yield contributed maximum towards divergence. The correlation study showed significant positive association of boll weight and lint yield with seed cotton yield per plant at both phenotypic and genotypic levels. So, increase in seed cotton yield per plant can be attained by the improvement of boll weight and lint yield in breeding programme. [ABSTRACT FROM AUTHOR]

In India, Gossypium barbadense is cultivated in niche areas in the south and central regions of the country, especially for its quality fibre. Initially, 50 barbadense accessions were screened for their stability across 2 years from the germplasm maintained at ICAR, CICR, RS germplasm, and stable diverse genotypes were selected for further breeding. The results indicated that ICB 262, ICB 174 and ICB 73 were early maturing. ICB 264, CCB 26 and ICB 73 showed tolerance to sucking pests due to their higher trichome density (TD), gossypol glands and epicuticular wax (ECW). G × E interactions were analysed for the 2019–2020 and 2020–2021showed that traits like number of bolls, single plant yield and fibre strength could express better during 2019–2020, single boll weight and micronaire were dominant in season 2. Traits like ginning percentage and fibre length were stable across environments indicating that their expression is genetically controlled. PCA results indicated that about 91.45% of total variability was explained by PCA1, 2 and 3. Diversity analysis grouped the accessions into four major clusters with two sub-clusters in groups 2, 3 and 4, hence forming seven groups. The minimum distance was observed between ICB 176 and CCB 11 (0.56) and the maximum distance was observed between ICB 174 and ICB 1 (3.11). [ABSTRACT FROM AUTHOR]

Little millet (Panicum sumatrense L.) is one of the neglected crops which is becoming popular as nutri-cereal. Development of high yielding stable cultivars may offer better economic return from this crop. Assessment of interrelationship among important economic traits helps to identify major yield component traits which could be selected for overall yield improvement hence development of superior genotypes. In this context, 50 genotypes of little millet were evaluated during kharif 2021, to identify important yield component traits through correlation and path analysis of 16 quantitative traits. Estimates of genotypic correlation coefficients were found to be higher than the estimates of phenotypic correlation coefficients, indicating that association were majorly under genetic control. It was revealed that direct selection based on fodder yield per plant, plant height and 1000 seed weight may help in augmenting grain yield in the experimental material, whereas, harvest index came out as the most important character for indirect selection. [ABSTRACT FROM AUTHOR]

A total of 64 medium duration rice accessions were evaluated for their genetic variability and genetic divergence during Rabi season 2020 at Pandit Jawaharlal Nehru College of Agriculture and Research Institute, Karaikal. Analysis of variance revealed significant differences for all the traits considered for the study. The traits spikelets per panicle and filled grains per panicle recorded high GCV as well as PCV thereby indicating that these traits would be improved effectively through selection. Other yield component traits viz., plant height, productive tillers per plant, spikelets per panicle, filled grains per panicle, fertility per cent, grain weight and single plant yield revealed high heritability coupled with high genetic advance, indicating that simple selection could be effective for improving these characters. The D2 values and hierarchical clustering analysis grouped the 64 germplasm into seven clusters. In both the clustering methods, the genotype Gold 44 was grouped under separate clusters indicating that, this is a diverse genotype among all the genotypes taken for study. Further, genotype AD 16124 was grouped under the same cluster in both the clustering methods with the highest cluster mean for grain yield per plant. Hence, this genotype could be efficiently utilized for the yield improvement programme in rice. [ABSTRACT FROM AUTHOR]

An experiment was conducted with a view to obtain information of genetic parameters of variation and character association for 13 quantitative traits in a set of 64 rice cultivars of Assam. The study revealed significant differences for all the traits under study. Highest genotypic coefficient of variation was observed for the trait biological yield followed by harvest index and grain yield. More than 80% heritability was observed for all the traits except grain yield, effective tillers per plant and biological yield. Genetic advance as per cent of mean was highest for biological yield followed by harvest index, filled grains per panicle and grain yield. Higher magnitude of genetic advance along with considerably high heritability observed for harvest index, filled grains per panicle and biological yield indicated that these traits could be considered for selection to obtain high genetic gain. Character association studies indicated that direct selection of 100 - grain weight, grain length, grain breadth, biological yield and harvest index, would bring about improvement in grain yield. Non-significant association of grain yield with important yield attributes viz., filled grain per panicle, tillers per plant and panicle length were due to their strong association with duration of genotypes, which in turn was negatively associated with grain yield. Recombination breeding and recurrent selection, therefore, could be suggested to break the negative linkage in order to achieve further genetic improvement. [ABSTRACT FROM AUTHOR]

In the current study, 20 elite rice genotypes were crossed with four CMS lines-CMS 23A, CMS 59A, CMS 64A and JMS 13A in a line x tester mating design and assessed alongside standard controls (JKRH 3333 and MTU 1001) to determine the best heterotic combinations in terms of grain yield and yield component characters at the Rice Research Centre, Rajendranagar. Eight restorer lines were found in Kharif 2018-19 based on pollen and spikelet fertility (MTU 1153, RNR 26015, RNR 28355, JGL 25960, MTU 1010, IET 27253, RNR 26085 and JAYA). The resulting 32 hybrids of 8 restorer lines and their corresponding CMS lines are studied for combing ability and heterosis. The degree of heterosis varied between traits. Three of the 32 hybrids under study had considerable standard heterosis for grain yield viz., JMS 13A x MTU 1153, CMS 59A x RNR 26015 and CMS 64A x MTU 1153, which outperformed the best checks JKRH 3333 and MTU 1001. The best experimental hybrid, JMS 13A x MTU 1153, yielded the most grain yield per plant, 62.89g (Table 1). Further testing of these three experimental hybrids will take place in areas conducive to extensive commercialization. [ABSTRACT FROM AUTHOR]

The present experiment was conducted with 16 germplasms and two varieties of snake gourd. The yield contributing traits such as node order of first male flower, node order of first female flower, days to first male flowering, days to first female flowering, internodal length, days to first harvest, single fruit weight, fruit length, fruit girth, number of fruits per plant, were studied to assess the genetic variability, heritability and genetic advance besides correlation and path coefficient analysis. The study of GCV and PCV in snake gourd germplasms exhibited variability for the traits viz., node order of first male flower, fruit length, number of fruits per plant, single fruit weight and fruit yield per plant including yield characteristics. Heritability and genetic advance as a percentage of mean indicated that the variation is due to a high degree of additive effect and hence the traits can be improved further through selection. Correlation and path analysis results showed that single fruit weight, number of fruits per plant and days to first harvest had a significant positive direct effect on number of fruits per plant. Hence these traits could be considered for yield improvement programmes in snake gourd. [ABSTRACT FROM AUTHOR]

A study was carried out to assess the genetic variability and association among yield attributing traits in 60 different safflower genotypes over six environments. The pooled analysis of variance (ANOVA) revealed that all attributes had a considerable degree of variation. The pooled analysis of variability parameters revealed that the phenotypic coefficients of variation (PCV) was higher than the genotypic coefficients of variation (GCV)for all of the characteristics evaluated, indicating that experimental variance contributed to total variation. Petal yield/plant and seed yield/plant had the highest PCV and GCV followed by number of capitula/plant, number of seeds/capitula, height of insertion of first branch, hundred seed weight, number of primary branches/plant, length of longest primary branches, number of secondary branches and height up to main capitula. Number of capitula/plant, seed yield/plant, petal yield/plant, height of insertion of first branch, number of seeds per capitula, hundred seed weight, number of primary branches/plant, length of the longest primary branches, number of secondary branches, height upto main capitula, capitulum diameter and plant height all had high heritability and genetic advance as percent of mean. Seedyield/plant showed positive, significant and directcorrelation with number of capitula/plant, number of seeds/capitulum, height up to the main capitulum, plant height, number of primary branches/plant, capitulum diameter, and hundred seed weight. Number of capitula/planthad the maximum direct effect on grain yield/plant followed by number of seeds/capitulum, hundred seed weight and petal yield/plant. Hence selection of these traits would improve seed and petal yield in safflower breeding program. [ABSTRACT FROM AUTHOR]

Eight parents and the 28 crosses of Indian Mustard (Brassica juncea (L.) Czern & Coss.) in two segregating generations, viz., F2 and F3 were studied for their genetic variability during the rabi seasons of 2020-21 and 2021-22, respectively. Observations were recorded for six morphological characters such as plant height (cm), primary branches per plant, secondary branches per plant, siliquae per plant, 1000 seed weight (g) and seed yield per plant (g). The PCV was found to be greater than the GCV and the difference between them was high in all the characters in both F2 and F3 generations. Most of the characters revealed a medium range of GCV and PCV. Moderate heritability was expressed by all the characters except primary branches per plant in F3 generation. The Genetic Advance as a percentage of Mean (GAM) was higher in most characters except in plant height. The character plant height was found to be positively correlated with seed yield per plant in both F2 and F3 generations, with secondary branches per plant in the F3 generation and negatively correlated with primary branches per plant in F3 generation. A high direct effect on seed yield per plant was exhibited by plant height and 1000 seed weight in both F2 and F3 generations and by Secondary branches per plant in the F2 generation and Siliquae per plant in the F3 generation. [ABSTRACT FROM AUTHOR]

Genetic divergence analysis in brinjal genetic resources consisting of landraces, related cultivated species and wild relatives based on 22 morphological descriptors revealed distinct variation between cultivated and wild genotypes for the plant, flowering and fruiting characters. The multivariate D2 analysis grouped the 30 accessions into eight clusters revealing a clear separation of wild relatives and cultivated types. The characters fruit yield per plant, leaf size and fruit number had high contribution towards the genetic divergence. SM-27 (cluster V), SM-25 (cluster III) and SM-23, SM-24, SM-20, SM-18, SM-10 and SM-8 (cluster I) were the promising accessions identified based on superior performance for three yield attributes viz., fruit weight, number of fruits per plant and fruit yield per plant. The accessions SM-25, SM-27, SM-28 (Solanum incanum) and SM-30 (Solanum insanum) of highly divergent clusters III, V and VIII respectively were identified as potential parents for future introgression breeding. [ABSTRACT FROM AUTHOR]

MTU 1010 is an early maturing and high-yielding mega rice variety widely grown in an area of 3 Mha. It is characterised by limited grain number and panicle branching. To improve the grain number in MTU 1010, an IRRI breeding line, IR121055-2-10-5 was utilized as donor to transfer yield-enhancing genes Gn1a and OsSPL14 (associated with increased grain number and better panicle branching, respectively) into MTU1010 by Marker-Assisted Backcross Breeding (MABB). At each backcross generation, foreground selection was carried out with Gn1a and OsSPL14- specific molecular markers, whilst background selection was done with a set of SSR markers polymorphic between the IR121055-2-10-5 and MTU1010. With the use of a gene-specific marker, homozygous BC2F2 plants carrying the yield-enhancing gene were identified and advanced through pedigree-method of selection till BC2F6 and best performing ten lines were selected and evaluated in replicated station trials for yield contributing traits, where grain number and brancing per panicle exhibited high significant and positive correlation with single plant yield. Three promising lines namely RP6353-5-8-13-24, RP6353-26-13-39-5 and RP6353-32-12-8-16 with higher grain number and yield than MTU1010 were identified and nominated for evaluation in Initial Varietal Trial-Aerobic (IVT-Aerobic) of All India Crop Improvement Programme on Rice (AICRP), of which RP6353-26-13-39-5 (IET28674), was promoted for further testing. [ABSTRACT FROM AUTHOR]

A study on heterosis in brinjal was carried out during the year 2019-20 at the Department of Genetics and Plant Breeding, Annamalai University. Seven genotypes were hybridised in full diallel fashion and the resultant 42 hybrids were evaluated along with parents in RBD. The mean squares of the 11 traits revealed significant differences among the entries. The hybrid ICO-345590 x Arka Kusumkar recorded high heterobeltiosis for fruit yield per plant and its associated traits except for fruit grith, fruit length, plant height, and days to first harvest. High standard heterosis was recorded by the hybrid ICO-344674 x ICO-383119 for plant height, ICO-344674 x Arka Kusumkar for days to first harvest, Arka Kusumkar x ICO-345590 for fruit length and ICO-345590 x ICO-545862 for fruit girth. The application of heterosis in brinjal will aid in the production of superior cross combinations, which will help meet the expanding demand for brinjal due to its bioactive properties. [ABSTRACT FROM AUTHOR]

Thirty-seven genotypes of coriander including six check varieties were analyzed for variability, correlation, path coefficients, and genetic divergence. Genotypes were grown in RBD with three replications and observations were recorded for 13 different quantitative traits. Secondary branches per plant and total oil content confirmed high values of GCV and PCV. Seeds per umbel, test weight, and total oil content exhibited high heritability along with high GA (% of mean). Both genotypically and phenotypically, seed yield per plant exhibited a positive and significant association with umbels per plant, umbellates per umbel, test weight, and harvest index. On seed yield per plant, umbels per plant reported the highest positive direct effect. Genetic diversity analysis grouped the 37 coriander genotypes into 6 different clusters with the maximum inter-cluster distance seen between clusters III and VI. Among the thirteen traits, test weight contributed largely to the total genetic divergence. [ABSTRACT FROM AUTHOR]

The most comprehensive study was undertaken to investigate genetic variability, character association studies and diversity analysis for yield and yield attributing traits in sixty-five maize genotypes along with five checks raised in Augmented block design II and observations were recorded on fourteen morphological traits. For all the traits, the analysis of variance revealed significant variance. PCV and GCV was high for anthesis silking interval. High genetic advance as per cent of mean along with heritability was recorded for anthesis silking interval, number of tassel branches, cob length, plant height and tassel height. This showed the effectiveness of selection for these traits. Character association analysis confirmed that grain yield per plant had a positive significant association with number of kernel rows per cob, number of kernels per row, cob breadth, cob length, 100 seed weight, shelling percentage and plant height. This implies that by selecting for these traits, grain yield per plant can be improved significantly. Path analysis for the attributed traits showed the direct effect of shelling percentage and plant height on single plant yield. Consequently, an emphasis on these traits could lead to the successful identification of higher yielding genotypes. Based on agglomerative hierarchical clustering, genotypes UMI1113, UMI1153, UMI 653-2-3, UMI1131-5 and UMI1076-5-4-2 can be used as parental lines in the hybridization programme. PCA biplot showed that number of kernel rows per cob, number of kernels per row, cob placement height, plant height and single plant yield mostly contributed towards variability. Furthermore, these parental lines should be assessed for their general combining ability and specific combining ability to generate stable and superior hybrids for better yield performance. [ABSTRACT FROM AUTHOR]

Drought occurrence during reproductive stage of rice leads to significant yield loss. Rice production has to be doubled to feed the ever increasing human population. As the yield levels are stagnated under favourable production system, improvement of yield under unfavourable environment is key to attain the projected target. Therefore, the present study was undertaken to improve the drought tolerance of popular rice variety ADT(R)45 by introgressing major effect quantitative trait loci (QTLs) conferring yield under drought (qDTY1.1, qDTY3.1 and qDTY12.1) through marker assisted backcross breeding (MABB). Through MABB, 117 BILs in the background of ADT(R)45 were developed with different combinations of qDTY QTLs. The BILs were evaluated under rainfed target production environment and observations on nine biometrical and yield traits were recorded. Variability analysis revealed presence of additive gene action for the traits viz., total number of tillers per plant, number of productive tillers per plant, hundred grain weight, yield per hectare and single plant yield. Hence, selection based on these traits will be effective to improve yield under drought stress. Association analysis showed total number of tillers per plant, number of productive tillers per plant, panicle length, hundred grain weight and spikelet fertility percentage were highly correlated with yield per plant. Comparison of BILs with different QTL combinations showed that BILs with single QTL (qDTY12.1) was better for most of the traits studied. BILs with single or two QTL combinations were found to perform better under rainfed condition, when compared to BILs with all the three QTLs. [ABSTRACT FROM AUTHOR]

The present investigation was performed to explain the genetic variability and association parameters of twenty traits in 30 F1s involving six parents differing in resistance against false smut in rice. Breeding materials were evaluated at hotspot location viz., HREC, Gudalur. The ANOVA revealed significant differences among the studied variables. Higher PCV over other coefficients of variation suggest the role of environment in trait expression. Disease related traits viz., NIP, NIT, NIGPa, PIT, PIGPa and agronomic traits viz., TNFPa, NCGPa, SSP, PH, HGW and SPY showed high magnitude of values for GCV, heritability and GAM indicating the role of additive gene action. Hence, selection of these traits may be effective. Correlation studies indicated that HGW and SPW showed positive significant association with SPY. Path analysis revealed that NIT, NIGPa, NIGP and PIP had negative direct effect and DFF, NPT, TNFPa, SSP, NSRPa and SPW had positive direct effect towards single plant yield. [ABSTRACT FROM AUTHOR]

A study was undertaken to study the correlation among yield contributing traits of coriander under two moisture regimns. The estimates of genotypic correlation coefficient were higher than their respective phenotypic correlation coefficients for most of the characters indicating strong genetic association between characters. The seed yield per plant showed positive and significant correlation with branches per plant, umbels per plant, seeds per umbel and test weight in normal environment, whereas with branches per plant and umbels per plant, under limited moisture environment. The highest direct and positive effect towards seed yield per plant was due to branches per plant followed by test weight, days to maturity, umbels per plants and seeds per umbel in a normal environment, whereas, in limited moisture environment, umbels per plant had the highest direct and positive effect followed by days to maturity, branches per plant, test weight and plant height. Thus branches per plant and umbels per plant had a high positive correlation as well as a high direct and positive effect towards seed yield per plant under both the environment and suggested that the aforesaid characters may be considered as important in breeding programmes aiming to coriander yield improvement. [ABSTRACT FROM AUTHOR]