RESUMO
grain yield and its component traits in 150 rice recombinant inbred lines, their parents and six checks at ICAR-IIRR, Hyderabad and AHRS, Kathalagere in wet 2022. The experiments were laid out in an augmented block design with five blocks. Phenotypic coefficients of variance were higher than genotypic coefficients of variance for all the traits across the locations. A joint consideration of high heritability in broad sense (h2) and genetic advance as per cent mean estimates were obtained for plant height, number of tillers, number of productive tillers, panicle length, number of grains per panicle, test weight, grain yield per plant suggesting that the traits were primarily under genetic control. Furthermore, high heritability (h2) and GAM recorded in these characters could be explained by additive gene action. However, high estimates (h2) combined with moderate GAM recorded for days to 50% flowering could be due to non-additive gene effect. Grain yield per plant recorded positive and significant correlation with the total number of grains per panicle (0.32***, 0.30***) and number of productive tillers per plant (0.21***, 0.26***) at both the locations. This result indicates that selection based on these two traits will be highly effective for yield improvement in rice.
RESUMO
Sorghum is a major staple food crop for the people in semi-arid areas of Asia. Post-flowering drought is a global constraint of sorghum production. The study aimed to improve stay-green characteristics of GS-23 sorghum variety by transferring stg3A and stg3B QTL`s respectively from donor genotypes K260 and K359w of ICRISAT by using marker assisted backcrossing. The experimental material comprised of six basic generations P1, P2, F1, F2, BC1 and BC2 developed from crossing GS-23 × K260 and GS-23 × K359 were genotyped using a set of 133 SNPs and 79 SSR markers. Whereas, 53 polymorphic SNPs among parents and backcross F1s for stay green trait at maturity were used to track introgression of stay green trait. Similarly,10 SSR markers were found to be polymorphic were used to track introgression of stay green trait i.e., stay green trait QTL`s stg3A and stg3B from donor parent K260 and K359w respectively in GS-23 background across backcross population and to identify plants that were homozygous for the desired allele. In which 02 SNPs SnpSB0039 and SnpSB0093 were identified as polymorphic for both K260 and K359w. Whereas 17 SNPs identified polymorphic for K260 and 34 SNPs for K359w. These SNPs were validated in both F1 and BC1F1 populations of both the crosses. Similarly, out of 10 SSR markers utilized, 02 SSRs were identified polymorphic to K260 and 02 SSRs were identified for K359w. Whereas 06 SSRs were polymorphic to both the parents K260 and K359w. Prominent 02 SSRs viz., Xtxp 141_Fam and Xgap84_Vic found to be more reliable and polymorphic to both the parents. These SSRs were validated in both F1 and BC1F1 populations of both the crosses. The genotypic analysis revealed the presence of favorable alleles in homozygous conditions at markers loci associated with stg3A and stg3B QTL`s in BC populations, suggesting successful introgression of stay green QTLs from the donor parents to the recurrent parent. Therefore, our study demonstrated the utility of marker-assisted backcrossing for drought tolerance improvement of locally adapted sorghum variety.
RESUMO
Rice lines need to be grown and evaluated for yield under different agro-ecological locations to identify stable and high-yielding lines for deployment in breeding programs. With this aim, a set of rice germplasm was evaluated for G×E in four different environments (E1-Dadesuguru-Wet 2020, E2-ICAR–IIRR-Dry 2019, E3-ICAR–IIRR-Wet 2020, E4-ICAR–IIRR-Dry 2020). The experimental trial was laid out in a randomized complete block (RCB) design with three replications at each location for 118 rice lines. Data on yield per plant was analyzed using the Additive Main Effect and Multiplicative Interaction (AMMI) and Genotype, and Genotype × Environment Interaction (GGE) models. The combined analysis of variance (ANOVA) manifested significant variations for tested genotypes, locations, years, genotype × year, and genotype × location interactions revealing the influence of environmental factors on yield traits. All four environments showed discrimination power, whereas E2 and E3 were found as the representative environment as they fall near the Average-Environment axis (AEA). The AMMI biplot PC1 contributed 79.20% variability and PC2 contributed 15.18% variability. From the GGE biplot analysis, the rice lines Phouren, JBB-631-1, and JBB-1325 were found to be the best and most stable. The rice lines Phouren, PUP-229, and TI-112 were stable in the first sub-group Dhadesugur-Wet 2020 (E1). The rice lines Langphou, and NPK-45 were stable in the second sub-group ICAR-IIRR-Wet 2020 (E3). Environment ICAR-IIRR-Dry 2019 (E2) was the third subgroup and the rice lines Moirangphou-Yenthik and TI-3 topped for the same. The ICAR IIRR-Dry 2020 (E4) environment formed the fourth subgroup where Phouren-Amubi, TI-128 and JBB-1325 topped the season. In conclusion, this study revealed that G × E interactions are significant for yield variation, and its AMMI and biplots analysis are efficient tools for visualizing the response of genotypes to different locations.
RESUMO
Common myna (Acridotherus tristis) and jungle myna (Acridotherus fuscus) forage in pure and mixed flocks of various sizes in fallow lands. These flocks were often found associated with drongos that forage individually on the insects herded out by the movements of the flocking myna. We report here the benefits and costs of such association to drongos and mynas. Drongos had a tendency to associate with larger (> 21) than smaller (<20) flocks irrespective of the species composition of the flocks. Drongos associated with larger flocks showed increased foraging trips and harvested more insects in a given time than those that were either isolated or were associated with small flocks. The food range of drongos and mynas differed significantly indicating that they do not compete with each other. Thus our results indicate that drongos are benefitted by this association; however this association neither benefits nor costs to the mynas. The association between the drongos and mynas therefore appears to be commensalistic.