Assessment of Genetic Variation and Character Association among Yield and Yield Attributing Traits in Sweet Corn (Zea mays L. saccharata) Inbred Lines

In this study, forty-six sweet corn inbred lines were evaluated to assess the variability and association among 11 yield and yield attributing traits at College Farm, College of Agriculture, Rajendranagar, PJTSAU. The traits plant height, ear height, cob length, cob girth, number of rows per ear, number of kernels per row, cob weight with husk and cob weight without husk have shown moderate to high range of PCV, GCV, heritability and genetic advance over mean displaying the importance of these traits in selecting superior sweet corn inbreds. Critical analysis of results obtained from correlation and path analysis revealed that the traits cob length, cob girth, number of kernel rows per ear and cob weight without husk posses high positive significant associations and positive direct effects. From this study it was concluded that cob length, cob girth, number of kernel rows per ear and cob weight without husk are the key traits to be given prime importance during selection for further improvement of production as they exhibited significant positive direct effects with cob weight with husk.

Screening of Tropical Maize Inbred Lines by Artificial Infestation for Resistance against Invasive Fall Armyworm in India

Aim: This study was aimed to find resistance sources against FAW. Study Design: Randomised Block Design. Place and Duration of Study: The Present study was conducted at Maize Research Centre, Hyderabad with promising germplasm during Kharif-2021, Rabi-2021-22 and Kharif-2022. Methodology: Field-collected FAW egg masses were reared using maize leaf- and stalk-based diet at 27 ± 1 °C, 60 ± 5% relative humidity and 12 h day length. The resulting neonates were used to infest the seedlings of 34 diverse tropical maize inbred genotypes. Results: A total of 15 genotypes were found to have recorded a leaf damage score of less than 5 with the least score recorded in BML 2 (3.24), followed by BML 11 (3.34), BML 7(3.37), BML 5 (3.37), BML 8 (3.49), CM 201 (3.60), BML 32-2 (3.91), CM 132 (3.97), BML 10 (4.01), BML 6 (4.02), BML 13 (4.34), CM202 (4.34), CM 131 (4.68), BML 90 (4.82), BML 45 (4.95) and displayed moderate resistance. Conclusion: Out of 34 inbred lines studied 15 were found to be moderately resistant to fall armyworm based on LIR and cob damage score under artificial infestation.

Genetic Analysis of Yield and its Components in Groundnut (Arachis hypogaea L.).

A total of 39 Groundnut accessions were used in this research work. Analysis of variance revealed significant difference among genotypes for all the seven characters studied. The magnitude of PCV and GCV was moderate to high for dry podyield and kernal yield. High heritability was recorded for hundred kernal weight, dry podyield and kernal yield. High heritability combined with high genetic advance was recorded for dry pod yield and kernal yield indicating that these characters are controlled by additive gene effect and phenotypic selection of these characters would be effective for further breeding purpose.

Association Analysis in Sesame (Sesamum indicum L.).

Character association and path analysis between yield and its contributing traits were studied in 54 sesame genotypes. Analysis of variance revealed the existence of significant differences among genotypes for all characters studied. Seed yield was significant positively correlated with number of capsules per plant, number of seeds per capsule, test weight and plant height. Path coefficient analysis indicated that number of seeds per capsule, number of capsules per plant was important traits to be considered for realizing the improvement in yield.

Genetic Variability Studies in Sesame (Sesamum indicum L.).

The evaluation of phenotypic variability, heritability and genetic advance in germplasm collections is important for both plant breeders and germplasm curators to optimize the use of the variability available. A total of 50 sesame accessions were used in this research work. Analysis of variance revealed significant difference among genotypes for all the nine characters studied. The magnitude of PCV and GCV was moderate to high for seed yield per plant, number of capsules per plant and number of branches per plant. High heritability was recorded for days to maturity, days to 50% flowering, seed yield per plant, number of capsules per plant and number of branches per plant. High heritability combined with high genetic advance was recorded for seed yield per plant, number of capsules per plant and number of branches per plant indicating that these characters are controlled by additive gene effect and phenotypic selection of these characters would be effective for further breeding purpose.

Genetic Variability and Association Analysis in Rice.

Genetic variability, character association and path analysis between yield and its contributing traits were studied in 49 Rice cultures. Analysis of variance revealed the existence of significant differences among genotypes for all characters studied. The magnitude of PCV and GCV was moderate to high for number of grains per panicle, test weight and grain yield. High heritability coupled with high genetic advance as per cent of mean was observed for test weight and grain yield indicating the role of additive gene in expressing these traits. Grain yield was significant positively correlated with number of grains per panicle, panicle length and test weight. Path coefficient analysis indicated that number of grains per panicle, test weight and productive tillers per square meter were essential traits to be considered for realizing the improvement in yield.

Genetic variability and association among the various characters in groundnut (Arachis Hypogaea L).

Seventy five groundnut genotypes were evaluated for yield and yield component characters indicated the existence of considerable genetic variation in the present investigation. The components of variance revealed that the phenotypic coefficient of variation (PCV) were higher than genotypic coefficient of variation (GCV) for all the characters studied indicating the role of environmental variance in the total variance. The magnitude of PCV and GCV was moderate to high for number of pods per plant, kernel yield, dry pod yield, hundred kernel weight, dry haulm yield. Heritability in broad sense was higher in most of the characters viz., hundred kernel weight, plant height, kernel yield, dry pod yield and number of pods per plant. High heritability coupled with high genetic advance as percent of mean was observed for hundred kernel weight, plant height, kernel yield, dry pod yield and number of pods per plant indicating the role of additive gene in expressing these traits. Pod yield was positively correlated with kernel yield, number of pods per plant, hundred kernel weight and shelling percent. Non significant positive association of pod yield noticed with dry haulm yield. However, significant negative association with plant height and non significant negative association with days to 50 percent flowering and days to maturity were observed. Direct positive effect of kernel yield, no of pods per plant and hundred kernel weight was revealed on pod yield. Hence, a direct selection criterion should be followed for traits viz., no of pods per plant and hundred kernel weight to improve the pod yield.

Effect of environment on genetic parameters of hybrid rice.

Field experiments were conducted using 68 hybrids, 17 parents and four checks across two different agroclimatic zones of Andhra Pradesh, South India during Kharif, 2008 and rabi-2008-09 to estimate the genetic variability parameters for yield and yield contributing characters. Pooled analysis over the environments, genotype and environment interactions were significant for traits like panicle weight, flag leaf length, flag leaf width, productive tillers per plant, filled grains per panicle, 1000 grain weight and grain yield per plant, implies differential behavior of genotypes under the four environments for these characters. The estimates of phenotypic coefficient of variation (PCV) were slightly higher than those of genotypic coefficient of variation (GCV) for all the traits studied across the seasons. Slight differences were observed for all the characters with regard to variability coefficients, heritability and genetic advance % of mean in different environments. Panicle weight, flag leaf length, flag leaf width, grains per panicle, yield per plant, 1000 grain weight and productivity per day were recorded moderate to high GCV, PCV, heritability, genetic advance % of mean, characters could be transmitted to the progeny and phenotypic based selection would be effective.

Correlation and path analysis studies in gallmidge resistant cultures of rice (oryza sativa l.).

Correlation and path coefficient analysis was carried out for yield and yield components in 21 gall midge resistant rice genotypes. Number of grains per panicle, days to 50% flowering and panicle length had a significant positive association with yield and also had a positive direct effect on grain yield. These traits contributed maximum to higher grain yield compared to other characters, thus, selection for these characters helps in selection of superior gallmidge resistant genotypes in rice.