Presence Of Sufficient Variability Research Articles

Genetic variability and association studies in Sunflower Inbreds

Genetic variability, heritability, genetic advance and association studies were carried out in 87 sunflower inbreds shared by different AICRP centres for six yield and its contributing traits. Results of ANOVA showed highly significant mean sum of squares for all the traits indicating presence of sufficient variability in the experimental material. Wide range of variation was noticed in plant height followed by seed yield and days to 50 % flowering. High phenotypic and genotypic coefficient of variation were recorded for head diameter, seed yield per plant and 100 seed weight. High heritability coupled with high genetic advance as per cent of mean was exhibited for seed yield indicated directional selection could be effective. Head diameter recorded strong correlation with seed yield followed by plant height and 100 seed weight and in turn these traits were also strongly intercorrelated.

Genetic Variability, GCV, PCV, Heritability and Genetic Advance Analysis in Fenugreek (Trigonella foenum- graecum L.)

An experiment was carried out using 55 (45 F1’S and 10 parents) genotypes of fenugreek to study the variability, heritability and genetic advance in percent of mean. The analysis of variance (ANOVA) revealed highly significant differences among the genotypes for the characters under study indicating presence of sufficient variability among the genotypes. Phenotypic coefficient of variation (PCV) was higher than the respective genotypic coefficient of variation (GCV) for all character that founded little effect on the characters on environment. The highest GCV and PCV were observed in the trait number of branches per plant followed by yield per plant. The high heritability coupled with moderate genetic advance in percent of mean were observed for number of branches per plant and yield per plant.

Estimation of heterosis for yield related traits and grain Zinc in rice (Oryza sativa L.).

The experiment consists of thirty hybrids generated in a Line x Tester mating design by crossing six lines with five male parents and studied along with two checks (BPT5204 and DRR dhan-45) for 16 characters contributing to yield and grain Zn content in rice. Analysis of variance exhibited significant differences among the genotypes for all the traits under investigation indicating the presence of sufficient variability in material and can be exploited. Among all the crosses, the hybrid, HUR-3022 x Dudhkander exhibited the highest significant positive heterobeltiosis for the number of effective tillers (91.94%), the number of grains per panicle (16.44%), 1000 grain weight (26.28%), grain yield per plant (214.03%) and biomass (225.12 %). HUR-3022 x Sathi exhibited the highest positive better parent heterosis for grain Zn content (38.37%). Standard heterosis over checks BPT-5204 and DRR dhan-45 of 214.03 and 40.07 per cent respectively, were exhibited by the cross, HUR-3022 x Dudhkander for yield plant per plant HUR-3022 x Sathi exhibited the highest positive economic heterosis of 69.42 and 60.26 per cent over BPT-5204 and DRR dhan-45 for grain Zn, respectively. Hence, these two hybrids viz., HUR-3022 x Dudhkander and HUR-3022 x Sathi can be exploited in breeding hybrids for high yield and high grain Zinc with further evaluation in multiple locations. Key words: L x T mating design, Rice, Standard heterosis, Zinc content.

Genetic variability studies in chilli (Capsicum annum L.)

A study was conducted to evaluate the nature and magnitude of genetic variability in 15 Chilli genotypes in a randomized block design with three replications. The analysis of variance revealed significant difference among 15 genotypes for all the character studied indicating the presence of sufficient variability in the studied material. Results revealed the presence of wide genetic variability. The genotypes were grouped into 5 clusters based on Mahalanobis D2 statistics using Torcher’s method. The clustering pattern of genotypes revealed that the genetic diversity was independent of the geographical diversity. Among the 5 clusters, maximum numbers of genotypes were found in cluster II, while clusters IV and V was found to be mono-genotypic. Among the 14 quantitative characters studied, number of seeds/fruits constituted a maximum of 26% contribution to the divergence, followed by fruit weight(g). Ranking of genotypes based on intra-cluster mean performance for these characters which are major contributors of genetic diversity revealed its usefulness in selecting parents for heterosis breeding.

Diversity and resistance components analysis of barley landraces to barley shoot fly (Delia flavibasis)

Barley shoot fly (Delia flavibasis) is one of the destructive insect pests of barley (Hordeum vulgare L.) at seedling stage. Resistance to barley shoot fly is governed by complex traits that derived from both morphological and/or biochemical characters of the plant. These host plant characters influence the relative degree of damage caused by the insect. The study aimed to evaluate phenotypic variability and interrelationships of factors influencing barley shoot fly resistance. Five hundred eighty-five landraces and ten cultivars were tested at Sinana Agricultural Research Center on station and Goba on-farm, during 2018 and 2019 main cropping seasons using augmented design consisting six blocks. High heritability percentage was obtained for yield and shoot fly resistance components like biomass (95.38%), early seedling growth vigour (91.41%), total tillers plant−1 (89.41%), fertile tiller plant−1 (88.91%), seedling colour (85.36), plant height (82.83%), 1000 seed weight (82.53%), number of seeds spike−1 (81.80%), spike length (81.11%), oviposition (65.74%) and dead heart (61.26%). Thus, this study revealed the presence of sufficient variability among the barley landraces in the country that can be exploited for germplasm enhancement. Furthermore, the defensive characters of accessions for shoot fly strongly influence the oviposition and dead heart percentage.

Estimation of Genetic Variability, Heritability and Genetic Advance for Seed Yield and Its Attributes in Sesame (Sesamum indicum L.)

The field experiment was conducted during July to October, 2018 at Castor-Mustard Research Station, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, Gujarat, India to access genetic variability, heritability and genetic advance for seed yield and its attributing traits in 45 genotypes of sesame. Analysis of variance revealed significant difference among genotypes for all the eleven characters which indicated presence of sufficient variability among the genotypes under study, hence there is an ample scope of selection for superior and desired genotypes to plant breeder for further crop improvement. The values of phenotypic coefficient of variation were slightly higher than that of genotypic coefficient of variation for all the traits studied. The high values of genotypic coefficient of variation and phenotypic coefficient of variation were recorded for seed yield plant−1, leaf area plant−1 and number of effective branches plant−1 indicated the presence of wide genetic variation for these characters. High heritability was recorded for 1000 seed weight, followed by leaf area plant−1, oil content, days to flowering, capsule length plant−1, number of capsules plant−1, days to maturity, seed yield plant−1 and number of effective branches plant−1 indicated that heritability may be due to higher contribution of genotypic component in these traits. High heritability combined with high genetic advance as percentage of mean was recorded for leaf area plant−1, seed yield plant−1, number of effective branches plant−1, number of capsules plant−1, 1000 seed weight and days to flowering indicating that these characters are controlled by additive gene effect and phenotypic selection of these characters would be effective for genetic improvement of seed yield in sesame.

HALF DIALLEL ANALYSIS OF SEVEN PEA CULTIVARS FOR SEED YIELD AND ITS COMPONENTS FOR F4 GENERATION UNDER SULAIMANI CONDITION

The present study was carried out at Qlyasan locations, in Kurdistan Region-Iraq, Agricultural Research Station, College of Agricultural Engineering Sciences-University of Sulaimani, according to half diallel mating system using seven pea cultivars (1-Avolla, 2-Americana, 3-Jeza, 4-Joneor, 5-Pack land, 6-Arvena and 7-Samara) with 21 F4 crosses. The genotypes were planted in a completely randomized block design with three replications. Highly significant mean squares due to genotypes were recorded indicating the presence of sufficient variability among genotypes for all traits. The mean squares due to gca and sca were significant for all the studied traits. The highest positive heterosis values estimated as the F4s deviation from mid parental values recorded by the cross 2×6 and 4×5 for almost all traits. Maximum positive gca effect values for seed weight plant-1, biological yield plant-1 and pods number plant-1 were recorded by parent 4, while parent 2 showed the best value for some components. The cross 4×5 was the best sca combiner for seed weight plant-1 and some its components including pods number plant-1, pod weight plant-1 and seed number pod-1. The type of gene action as controlled the inheritance of all characters was over dominance except 100-seed weight. Heritability in broad sense was found to be high for all treats except seed number pod-1 which was moderate, while at narrow sense it was high for average pod weight, pod length, seed weight pod-1 and 100-seed weight.

Heterosis and combining ability studies in sesame (Sesamum indicum L.)

Heterosis and combining ability analysis were carried out with three lines and nine testers during kharif 2018. The mean sum ofsquares due to parents showed significant differences for most ofthe characters, except oil contentindicating the presence ofsufficient variability among the parents. The mean squares due to hybrids were significant for almost all the characters studied. The estimation of gca variances were lower than sca variances which indicated the predominance of non-additive gene action for plant height, days to 50% flowering, days to maturity, number of effective branches/plant, number of capsules/ plant, number ofseeds/capsule, harvest index, seed yield/plant, capsule bearing length and additive gene action for oil content. Non-additive genetic variances may be utilized to increase the yield levels by heterosis breeding. The parents, TKG-22, GT-10 and RT-372 were good general combiners for seed yield and contributing characters. The best specific crosses, RT-351 × TKG-22, RT-54 × TKG-22 and RT-54 × RT-372 were most heterotic hybrids for seed yield and found promising for yield contributing characters. These crosses involved average × average, average × poor, average × good parents.

Genetic variability, heritability and genetic advance for yield and its contributing traits in rice (Oryza sativa L.)

The experiment on 125 genotypes (20 lines, 5 tester and 100 F1’s) including a check viz., Pusa Basmati 6 of rice (Oryza sativa L.) was conducted to work out the genetic variability, heritability and genetic advance effects of their various attributes on grain yield. The mean squares due to treatments, parents and crosses were highly significant for all the fifteen characters indicated the presence of sufficient variability in the study materials. PCV was higher than the genotypic GCV for all the traits. High heritability (>60%) were recorded for characters viz., grains per panicle, spikelets per panicle, L:B ratio, kernel length, panicle length, kernel breadth, flag leaf area, grain yield per plant, plant height, panicle bearing tillers per plant, 1000-grain weight, harvest-index and spikelet fertility. The high genetic advance in percent of mean (>20) was recorded for grains per panicle fallowed by spikelet’s per panicle and L:B ratio for this parameter. High heritability coupled with high genetic advance in per cent of mean were observed for the characters like grains per panicle, spikelets per panicle, and L:B ratio. High heritability and genetic advance account that the additive nature of gene action and so that these characters are directly selecting for further advancement of rice crop.

Genetic variability and inter-relationship studies in advanced interspecific derivatives of chickpea

The present study was undertaken to assess the variations and association among yield and its contributing traits in interspecific derivatives of chickpea. One hundred thirty chickpea interspecific derivatives of four wide crosses were evaluated for various agro-morphological traits. The analysis of variance revealed the presence of sufficient variability among the recombinant lines for all the traits studied. Genotypic and phenotypic coefficients of variation were found to be higher for seed yield per plant, 100-seed weight, plant height and pods per plant. Likewise, moderate PCV and GCV were observed for biological yield per plant and harvest index. Selection will be effective for traits such as plant height, 100-seed weight, biological yield per plant, number of pods per plant, seed yield per plant and harvest index as they showed high heritability along with high genetic advance. Correlation and path coefficient analysis revealed that higher seed yield per plant can be obtained by selecting derivatives with high biological yield per plant, number of pods per plant, 100-seed weight and harvest index. Overall interspecific recombinant lines viz; R-31 (Cross I - PUSA 372 X ILWC 229), R-12, R-27 and R-30 (Cross II - PBG 5 X ILWC 229), R-3 (Cross III -PBG 5 X ILWC 246) and R-6 (Cross IV - BGD 72 X ILWC 246) were found superior over the best check, Him Palam Chana 1 (DKG 986).

Genetic Analysis for Yield and Yield Attributing Traits in Cowpea (Vignaunguiculata L. Walp)

The present investigation was conducted comprising of the parental lines and F1 progenies derived from a 6 x 6 diallel cross among cowpea varieties, excluding reciprocals. Analysis of variance revealed presence of sufficient variation among the genotypes for all the characters studied. For seed yield both GCA and SCA variances were significant, while GCA variance was significant for pods per cluster and SCA variance was significant for plant height, number of primary branches and pod length. Variety JCC-4 followed by UPC-622 were good general combiner for yield and yield attributing characters. Maximum SCA effect for seed yield per plant was observed with cross JCC-1 x JCC-4 followed by JCC-3 x JCC-4. Genetic analysis revealed that both additive (D) and dominance (H1 and H2) components were involved in controlling most of the characters. The predominant role of non-additive gene action was evident from relatively higher magnitude of dominance components, including H1, H2 and h2.

English

Tigernut (Cyperus esculentus L.) is a nutritious crop of the sedge family. In Ghana available local accessions have not been collected and characterized for conservation and utilization purposes. The objective of this study was to collect, conserve and characterize twenty-four local accessions of tigernut in Ghana based on agro-morphological traits. The ANOVA revealed significant (p<0.05) differences among the accessions for all the traits studied except for hundred nut weight, indicating the presence of sufficient variability among the accessions. The hierarchical cluster analysis put the accessions into six major groups confirming a wide range of diversity among the accessions. The biplot of the principal components analysis revealed the scattering of the accessions in all the quarters which further suggest a higher level of variability among the accessions studied. The PCA also revealed that the first five PC accounted for a total of 88.4% variability among the accessions. PC1 accounted for 45.6% of the total variation with an Eigenvalue of 6.84. The correlation analysis among the traits showed significant and positive correlation between number of nuts and good nuts (r=0.94) and detached nuts and attached nuts. However, there was significant negative correlation among nut width and detached nuts (r = - 0.88) and harvest index and biological yields (r = - 0.77). Based on the study, accessions TPY, CCB, BB, DY, ADL, KB, KAY, WY1 and BKB which recorded high values for number of nuts, good nuts, nut length, nut width and harvest index could be included in breeding programs for varietal development of tigernut in Ghana. Key words: Tigernut, Cyperus esculentus, Ghana, morphological characterization, cluster analysis, germplasm, principal component analysis, correlation, variability.

Genetic analysis of nutritional and antioxidant traits in eggplant (S. melongena)

Six generations of eggplants (P1, P2, F1, F2, BC1 and BC2) obtained from two crosses SM001-07 x ST004-03 and SM001-07 x San005-01 were grown in an open field using Randomized complete Block Design with four replications. The experiment was conducted to determine gene effects for the inheritance of twelve nutritional and antioxidant traits in eggplant using generation mean analysis. The analysis of variance showed significant differences for most traits indicating the presence of sufficient variation in the eggplant materials under study. Additive-dominance effect was adequate to demonstrate the genetic variation and its significance in the inheritance of protein and magnesium contents, while non-allelic interactions were observed to be important for iron, zinc and total phenol in both crosses. The study also showed low values for dominance and environmental variances that resulted in high heritability values for most traits. Therefore, to improve these traits population improvement approaches (recurrent selection or pure line) followed by delayed selection in segregating generation would yield better results.

English

The present study consists of 14 sorghum genotypes evaluated at Bako, Jimma and Mechara research centers to study genetic variability and interrelationships of traits with grain yield. The experiment was conducted by using randomized complete block design (RCBD) with three replications during 2014 and 2015 main rainy season. Data on important agronomic traits were collected. The combined analysis of variance (ANOVA) across years and locations showed highly significant differences among genotypes for all traits, indicating the presence of sufficient variability among the genotypes. Environmental coefficients of variation (ECV), genotypic coefficients of variation (GCV) and Phenotypic coefficient of variation (PCV) ranges of the study are days to 50% maturity (DM, 0.49) to number of seeds per panicle (NSPP, 6.11); DM (0.31) to PAS (16.99) and DM (1.12) to GY (20.86) in the same order. High h2BS values were observed in hundred seed weight (HSW, 76%), DS (70%), plant height (PH, 65%) and PAS (63). High value of genetic advance as a percentage of mean (GA% &micro;) was recorded by PAS (27.42%), PH (26.29%) and DS (20.65%) and moderate amount of GA%&micro; was recorded by HSW (11.78%) and HW (11.08%). High h2BS coupled with high to moderate GA%&micro; was reported for PH (65 and 26.29%); HSW (76 and 11.78%); PAS (63 and 27.42%) and DS (70 and 20.65%) indicating PH and HSW are controlled by additive gene action. GY had strong positive genotypic association with HW (0.99) followed by NSPP (0.96). These results suggested that any positive increase in such traits will increase the grain yield. The genotypic path analysis also showed that head weight per plot (HW, 1.96) and PH (0.55), had high and very high positive direct effect, respectively on GY indicating that these traits are the most important yield component traits. Hence, due consideration should be given to these traits while selecting promising lines. Key words: Correlation coefficient, genetic advance, heritability, path coefficient, sorghum. &nbsp

Variation and Relationships among Agronomic Traits in Durum Wheat [Triticum turgidum(L.) Thell. ssp.turgidumconv.durum(Desf.) MacKey] under South Mediterranean Growth Conditions: Stepwise and Path Analyses

Relationships among agronomic traits and grain yield were investigated in 56 genotypes of durum wheat (Triticum durumDesf.). The results indicated the presence of sufficient variability nearly for all measured traits. Heritability and expected genetic gain varied among traits. Aboveground biomass, harvest index, and spike number were the most grain yield-influencing traits. Early genotypes showed above-average grain and biological yields, spike number, and lower canopy temperature. Assessed genotypes were clustered into three groups which differed mainly for biological, economical, straw, and grain yields, on the one hand, and plant height, chlorophyll content, and canopy temperature, on the other hand. Selection for direct use from clusters carrying best combinations of yield-related traits and crosses to be made between genotypes belonging to contrasted clusters were suggested to generate more variability. Selection preferentially for spike number, biological yield, harvest index, and canopy temperature to accumulate favorable alleles in the selected entries for future uses is suggested.

GENETIC DIVERGENCE STUDIES IN BLACKGRAM (Vigna mungo L.) FOR YIELD AND QUANTITATIVE TRAITS

The genetic divergence was estimated in 21 blackgram genotypes, using Mahalanobis D2 statistics. The experiment was conducted at Plant Breeding Farm, Department of Genetics and Plant Breeding, Faculty of Agriculture, Annamalai University during January 2017. Analysis of genetic variance indicated the presence of sufficient variation among the selected genotypes. Based on 11 morphological and quality characters namely, days to first flower, plant height (cm), number of primary branches, number of clusters per plant, number of pods per plant, pod length (cm), pod weight (g), number of seeds per pod, seed size (cm), 100 seed weight (g), yield per plant (g), these genotypes were grouped into 5 clusters showing fair degree of relationship between geographical distribution and genetic divergence. Cluster I, with 6 genotypes, was the largest cluster followed by cluster IV and V with 5 genotypes. The intra cluster distance was maximum (D=809.83) in cluster V. The maximum inter cluster distance (D2=2932.162) was recorded between cluster II and III. All cluster mean values are distributed in relatively distant clusters. Traits like yield per plant (70.47%) followed by 100 seed weight (17%) were the major contributors to total genetic divergence.

Genetic variability and association studies in pearl millet for green fodder yield and quality traits

In the present study, a total of 22 pearl millet genotypes were evaluated during kharif, 2017. The genotypes were analyzed for genetic variability, correlation and path coefficients. Analysis of variance revealed highly significant differences among the genotypes for all the 12 characters viz., plant height, number of tillers per plant, number of leaves per tiller, leaf length, leaf breadth, leaf-stem ratio, dry matter yield per plant, green fodder yield per plant, crude protein, crude fibre, fat content and ash content studied, indicating the presence of sufficient variability in the experimental materials of pearl millet genotypes. The estimates of genotypic coefficient of variation were lesser than that of phenotypic coefficient of variation for all the traits except ash content per cent, indicating the role of environmental influence over the characters studied. High heritability with high genetic advance as per cent of mean was observed for green fodder yield per plant, dry matter yield per plant, fat content, crude protein content and ash content. This indicated the prevalence of additive gene action in their inheritance; hence selection of these traits would facilitate the improvement of both fodder yield and quality. Correlation and path analysis revealed that the traits viz., plant height, leaf breadth and dry matter yield per plant might be responsible for increasing the green fodder yield per plant in fodder pearl millet.

Analysis of the phenotypic variability of twenty f&lt;sub&gt;3&lt;/sub&gt; biparental populations of bread wheat (&lt;i&gt;Triticum aestivum&lt;/i&gt; L.) evaluated under semi-arid environment

This research was conducted to screen and analyse the variability within twenty F 3 populations of bread wheat ( Triticum aestivum L .) generated by Line x Tester mating design. The results indicated the presence of sufficient variability within and between F 3 populations for the eight measured variables, which represent plant phenology, physiology, yield and yield components. Different populations have been identified to improve the measured variables separately. The number of spikes appeared to be the most important determinant of grain yield. PCA and cluster analyses indicated that the Acsad1069/El Wifak and Acsad1135/Hidhab, with a relatively high grain yield, aboveground biomass and 1000 grains weight, are the best F 3 populations to improve the productivity. However, Acsad899/Rmada and Acsad1135/Rmada populations were earlier and had a low number of spikes. These populations had also favorable genes for heat tolerance. Keywords : Triticum aestivum L .; Variability; Selection; Tolerance; Yield.

Genetic variability, trait association and path analysis of yield and yield components in greengram [Vigna radiata (L.) Wilczek

An experiment was conducted to study the extent of variability, interrelationship and direct and indirect effects of component characters on seed yield in greengram during the kharif 2016 for 12 quantitative characters. Analysis of variance revealed significant differences for all the characters studied, indicating sufficient variation among genotypes. The magnitude of genotypic coefficient of variation and phenotypic coefficient of variation was high for primary branches per plant and clusters per plant, indicating the presence of sufficient variation in these traits. Clusters per plant, pods per plant, seeds per pod, seed yield per plant, pod length, primary branches per plant, seed index, plant height, biological yield per plant and harvest index showed high heritability accompanied by high genetic advance, indicating that the heritability was due to additive gene effects and selection may be effective. Seed yield per plant exhibited significant positive correlation with pods per plant (0.982**), clusters per plant (0.977**), primary branches per plant (0.795**), harvest index (0.749**), seeds per pod (0.417**) and biological yield (0.315*) at both the phenotypic and genotypic levels. The characters harvest index (0.748), biological yield (0.649), pods per plant (0.133), seeds per pod (0.095) and primary branches per plant (0.016) exhibited positive direct effect with seed yield. Harvest index and biological yield per plant exhibited high positive direct effect accompanied by significant positive correlation with seed yield. So, these characters can be used as selection criteria for yield improvement in greengram.

Assessment of Genetic variability, Heritability and Genetic advance in Chilli (Capsicum annuum L.)

The present experiment was carried out at vegetable research center of G B Pant University of Agriculture and Technology, Pantnagar, Uttarakhand during the spring summer season of 2014 in randomized block design with three replication to assess genetic variability, heritability and genetic advance as percent of mean for various growth, yield and quality traits. Data were recorded on plant height, canopy width, days to 50% flowering, days to 50% fruiting, number of fruits per plant, average fruit weight, stalk length, fruit body length, fruit yield per plant, ascorbic acid content, TSS, Anthracnose incidence, LCV incidence and total fruit yield per hectare. Analysis of variance revealed significant differences among the genotypes for all the traits studied indicating the presence of sufficient variability in the studied material. The phenotypic coefficient of variation (PCV) was higher than genotypic coefficient of variation (GCV) and the difference between PCV and GCV was narrow for most of the characters revealing little influence of the environment in the expression of these traits. High magnitude of PCV and GCV were observed for days to 50% flowering, number of fruits per plant, average fruit weight, fruit yield per plant, fruit body length, ascorbic acid, TSS, Anthracnose, leaf curl virus incidence and total fruit yield per hectare suggesting the existence of wide range of genetic variability in the genotypes for these traits. High heritability coupled with high genetic advance as percent of mean was observed for all the traits except canopy width and stalk length revealed these traits are under the control of additive gene action and lower influence of environmental factor in the expression of these traits with possibility for genetic improvement through simple selection.