Search

The study was evaluated to estimate mineral profiles and find out selection criteria for high foliage yielding cultivars by assessing the magnitude of genetic variability, heritability, genetic advance, association, and contribution of characters of sixteen stem amaranth genotypes in a randomized block design with three replications. Based on high heritability and high GA and GAPM and close values between Vg vs. Vp and GCV vs. PCV, all the traits could be selected to improve the foliage yield of stem amaranth. A significant and desirable positive correlation was observed for Fe, Ca, Mn, K, and leaves plant-1 both at genotypic and phenotypic levels. These five traits could be selected for improving the foliage yield of stem amaranth as these traits exhibited less influence on the environment. The insignificant genotypic correlation values were observed between mineral vs. mineral and mineral vs. foliage yield and yield contributing agronomic traits, which indicate that selection for high mineral content might be possible without compromising yield loss. A high to moderate direct effect along with a significant correlation was found in Fe, K, Ca, and Mn. Fe, K, Ca, and Mn had the most significant contribution to foliage yield of stem amaranth as these traits exhibited considerable positive direct effects and significant correlation coefficients on foliage yield. The accessions AS7, AS4, AS5, AS14, and AS16 had high foliage yields containing moderate to high mineral profiles. These five accessions could be selected as high-yielding cultivars. Selection could be made based on Fe, K, Ca, and Mn content to improve stem amaranth. The accessions AS7, AS4, AS5, AS14, and AS16 could be used as high foliage yielding and mineral profiles enrich cultivars.

Twenty salt-tolerant breeding lines of T. Aman rice were studied under field conditions at the experimental farm of the Department of Genetics and Plant Breeding, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh. The experiment was conducted following Randomized Complete Block Design (RCBD) with three replications to estimate the genetic variations in yield and yield-related traits, and their interrelationship and to assess the direct and indirect effects of different yield-related traits on grain yield for the selection of high-yielding T. Aman rice. Twelve characters viz., days to flowering, days to maturity, plant height (cm), tillers per hill, panicles per hill, flag leaf length (cm), panicle length (cm), panicle weight (g), filled grains per panicle, spikelet fertility percentage, 100-grain weight (g) and grain yield per m2 (kg) were studied. The genotypes differed significantly for all the traits studied indicating the wide range of variations existed across the genotypes. The analysis of variance of all characters studied was highly significant that revealed a wide range of variability among the newly developed 20 salt-tolerant genotypes of T. Aman rice. The genotypes BU1, BU4, BU6, BU7, and BU14 had high grain yields and could be directly selected as high-yielding varieties. Based on all genetic parameters, all the traits could significantly improve the grain yield of salt-tolerant lines of T. Aman rice. The correlation coefficient revealed that the genotype selected based on days to flowering, days to maturity, plant height (cm), panicles per hill, flag leaf length (cm), panicle weight (g), filled grains per panicle, and spikelet fertility (%) and 100-grain weight directly would significantly contribute to grain yield of 20 salt-tolerant genotypes of T. Aman rice. However, considering the genotypic correlations and path coefficients, direct selection on the basis of panicles per hill, panicle weight, plant height, flag leaf length, filled grains per panicle, spikelet fertility (%), days to flowering, and days to maturity would significantly improve the grain yield of salt-tolerant T. Aman rice genotypes.

Seven advanced breeding lines developed through hybridization breeding program and a popular cultivar were used to study variability, heritability, character association, and path coefficient analysis in rice for grain yield and its related agronomic traits. The results indicated that genotypes differed significantly in terms of grain yield and its related agronomic traits. Pronounced variations were observed for all the traits except for growth duration and harvest index. High genetic variability was observed for number of filled grains per panicle, number of secondary branches per panicle, plant height, spikelet sterility (%), grain yield per hill, number of primary branches per panicle, 1000-grain weight, duration of flowering and maturity, number of tillers per hill, number of panicles per hill, and panicle length. Based on high heritability and high GA and GAPM along with close values between σ2g vs. σ2p and GCV vs. PCV all the traits (except for harvest index, number of primary branches per panicle, days to maturity, and days to flowering) could be selected for improving the grain yield of rice as these traits exhibited less influence of environment. The significant and desirable correlations were observed for number of filled grains per panicle, number of secondary branches per panicle, spikelet sterility (%), days to flowering both at genotypic and phenotypic level. Considering genetic parameters, correlation, and path coefficient analysis, direct selection based on number of filled grains per panicle and spikelet sterility would significantly increase the grain yield of rice. So, direct selection based on these traits would be effective for the improvement of these breeding materials. The residual effect was found 0.1386 which indicated that 86.14% of the variability was accounted for grain yield and yield contributing traits included in the present study. Rest 13.86% variability might be controlled by other yield contributing traits that were not included in the present investigation.

Twenty five vegetable amaranth genotypes were evaluated to investigate the antioxidant vitamins and minerals composition and its genetic variability in a RCBD with three replications at Bangabandhu Sheikh Mujibur Rahman Agricultural University in Bangladesh during kharif1 season 2012 and 2013, respectively. Significant Mean Sum of Square revealed a wide range of genotypic variability among traits. Vegetable amaranth was rich in iron, zinc, manganese, magnesium and potassium. Ten strains gave the best (more than 5 kg) foliage yield with rich in antioxidant minerals and vitamins. Selection of these genotypes would be economically useful for antioxidant vitamins, minerals and yield aspects. On the other hand, eight genotypes had high amounts of antioxidant vitamins and minerals with below average foliage yield and could be utilized as donor parents for introgression of genes in vitamins and minerals deficient lines. Considering genetic parameter six traits i e., Fe, Zn, Mn, ascorbic acid, number of leaves plant and foliage yield would be selected for the improvement of vegetable amaranth genotypes under study. However, correlation study revealed that selection based on Fe, Mn, ascorbic acid and number of leaves per plant could lead to increase the foliage yield of vegetable amaranth strains. Insignificant genotypic correlations between foliage yield with most of the antioxidant vitamins and minerals traits indicating that selection for high vitamins and minerals content might be possible without compromising yield loss. Based on mean, genetic parameters and correlation coefficient values, five vegetable amaranth genotypes i. e., AA19, AA10, AA3, AA24 and AA7 might be selected as high vitamin and minerals containing high yielding vegetable amaranth varieties.