High Genetic Advances Research Articles

Morpho-phenological characterization and genetic analysis of dolichos bean germplasm from Uttar Pradesh, India

AbstractThe true characterization of elite germplasm is of utmost importance for accelerating the crop breeding programme. The Indian dolichos bean [Lablab purpureus (L.) var. typicus Prain] has the potential to improve nutritional and food security. In the present investigation, a total of 21 genotypes of dolichos bean, comprising local collections mainly, along with one standard check (Kashi Sheetal) were evaluated in a complete randomized block design with three replications for two consecutive years, 2021–22 to 2022–23 for the perusal of the genetic variability. Analysis of variance revealed significant differences among all the genotypes for all the characters. PCV and GCV estimates revealed very little influence of environment on the expression of traits under study. High heritability (>90%) estimates coupled with high genetic advance as a percent of the mean were observed for flower attributes, pod length, average weight of 10 pods, pod yield and protein content. The principal component analysis revealed that the first two components cumulatively accounted for more than 50% of total variability. The present investigation revealed that the genotypes, RLBDL-S-8, RLBDL-S-14 and RLBDL-S-4-5 were stable across the years and genotype RLBDL-S-8 exhibited the highest yield potential, which can be used effectively in the development of high yielding varieties of dolichos bean in the Bundelkhand region. The study also revealed the presence of wide genetic variability in the studied local accessions which is a prerequisite for the genetic improvement of crop plants. High heritability and genetic advancement indicated the scope of selection in the crop improvement.

Performance and Stability of Improved Cassava (Manihot esculenta Crantz) Clones in Demand Creation Trials in Nigeria

Cassava fresh root yield and dry matter content constitute major determinants of demand by end-users. Increased demand for the seeds of improved varieties will facilitate the development of a sustainable seed system. However, for wide acceptability, there is a need to continuously evaluate candidate varieties for stability across different agroecological zones. Participatory Demand Creation Trials (DCTs) were established to evaluate cassava varieties with farmers and processors utilizing the best agronomic practices. The multi-year DCTs were conducted in 20 environments (7 locations) during the 2016–2017, 2017–2018, 2018–2019, and 2019/2020 cropping seasons with two replications. The plot sizes were 320 m2 with a spacing of 1 m × 0.8 m. The traits evaluated were Plant Vigor (PV), root number, fresh yield, dry yield, Dry Matter Content (DMC), and bundle estimation. The traits were subjected to a GGE biplot in R software to identify high-yielding and stable genotypes. Results obtained from the 20 environments showed that genotype (G), environment (E), and GXE interaction effects were significant (p < 0.01) for all the traits but PV. The heritability ranged from 56% (PV) to 96% (DMC). The average fresh yield t/ha ranged from 25.5 (IBA30572) to 35.4 (IBA980505). The DMC ranged from CR36/5 (36.1%) to IBA010040 (30.7%). The dry yield ranged from 8.8% (IBA30572) to 11.4 (IBA980505). Estimated bundles ranged from 13.5 (CR36-5) to 15.7 (IBA950289). Three varieties, IBA961632, TMEB419, and CR36/5, were identified as the most promising high dry matter content varieties for cassava processors and farmers in Nigeria, and genotype IBA961632 was the most stable. The study revealed greater genotypic effects than from the environment and high genetic advances.

Hybrid evaluation for yield and yield attributes in Okra (Abelmoschus esculentus L. Moench) during monsoon season

The present investigation aimed to evaluate Okra hybrids for growth and yield characteristics during the monsoon season in the dry and humid regions of Telangana. The experiment was conducted under augmented design with nineteen numbers of checks over 335 okra hybrids. The analysis of variance showed significant differences for all the traits under adjusted and unadjusted treatment effect and moreover checks also, except the number of days for flowering. The comparative mean performance deduced the hybrids like 21A014, 21A046, 21A064, 21A077, 21A079, 21A095, 21A112, 21A121, 21A181, 21A235, 21A252 and Check-12 has performed well under monsoon condition for various characters. The genetic parameter revealed that the traits like number of branches, stem internode distance (cm), average fruit weight (g), seed count, yield per plant (g/plant) and yield per hectare (t/ha) resulted in moderate Phenotypic Coefficient of Variation (PCV), Genotypic Coefficient of Variation (GCV), with high broad sense heritability coupled with high Genetic Advance over Mean (GAM). The selected hybrids can be potentially evaluated for the summer season in various locations for yield prospective and viral tolerance.

Effects of Tree Trunk, Branch and Leaf Traits On Morphological Diversity of Litchi Chinensis Sonn.

Twenty five morphological traits of tree trunk, branch and leaf were employed to discriminate 30 Indian Litchi (Litchi chinensis Sonn.) genotypes as well as to assess their morphological diversity at ICAR-NRC on Litchi, Muzaffarpur, India. Litchi genotypes were highly diversified. Twelve qualitative and 13 quantitative traits exhibited high degrees of variability. High phenotypic and genotypic coefficients of variation were recorded for tree volume (31.26 and 31.15%), leaf area (22.27 and 21.87%) and thickness of leaf (21.56 and 20.89%). High heritability coupled with high genetic advances was recorded for plant height (97.92%), crown diameter (99.40%), tree volume (99.34%), leaflet number (93.28%), rachis length (91.45%), petiole length (96.45%), petiolule length (95.91%), leaf length (93.07%), leaf area (96.39%) and leaf thickness (93.89%), indicating ample scope of improvement for these traits through selection. Bangladesh J. Bot. 52(1): 197-202, 2023 (March)

Agromorphological Characterization of Maize Hybrids and Estimation of Genetic Parameters in Mid-Hills of Far-West Nepal

The experiment was laid out in alpha-lattice design with two replicates of each genotype which comprised twenty-three heat-tolerant maize hybrids received from CIMMYT-Mexico and three check varieties. These treatment genotypes were evaluated at the Agronomy farm, Gokuleshwor College, Baitadi, Nepal, during the spring season of 2021. ZH191065 and ZH191158 were found to be the tallest (307.2 cm) and the shortest (227.6 cm) genotypes, respectively. High heritability (>60%) with high genetic advances in most traits, ensures the predominance difference of the genetic components observed among accessions. The presence of differences among genotypes showed that selection is possible by evaluating the days of 50% anthesis, days of 50% silking, anthesis-silking interval, number of ears per plant, number of grains per row, number of rows per cob, cob length, cob diameter, and grain yield; most of these evaluated morphological traits were found highly correlated with grain yield of varieties, suggesting that indirect selection achieves improvement for high yield. Based on yield ranks, ZH 19782, ZH 19961, and DKC 9108 could be promoted as potential higher-yielding heat-tolerant maize hybrids for Nepal.

Genetic Variability and Association of Yield and Yield-Related Traits under Moisture Stress in Common Bean Genotypes (Phaseolus vulgaris L.) at Melkassa and Miesso, Ethiopia

Twenty-five common bean genotypes were evaluated to assess the genetic variability, trait association, and determine the direct and indirect effects of traits on seed yield. The genotypes were grown in a lattice design at the research farm of the Melkassa Agricultural Research Center, Melkassa and Miesso, in the 2018 cropping season. Analysis of variance revealed that significant differences were observed among the genotypes at individual locations. The phenotypic coefficient of variation values were moderate for number of nodes, seeds per pod, plant height, and hundred seed weight at Melkassa. Moderate genotypic coefficient of variation values were obtained for pods per plant and seeds per pod. At Miesso, moderate phenotypic coefficients of variation values were recorded for number of nodes, hundred seed weight, and plant height. High heritability estimates were obtained for seed yield and hundred seed weight at Melkassa and for seed yield at Miesso, indicating that selection could be fairly easy and improvement is possible using these traits in a common bean breeding program. High genetic advances were obtained for seed yield and pods per plant at Melkassa, while moderate genetic advances as a percent of the mean were attained for plant height, hundred seed weight, and seeds per pod. Similarly, at Miesso, high and moderate genetic advances as percent of mean values were obtained for seed yield and hundred seed weight, respectively. Seed yield showed positive and significant phenotypic association with days to flowering, internode length, and pods per plant at Melkassa and had positive and significant phenotypic association with seeds per pod and hundred seed weight at Miesso. Hence, selection of those genotypes based on the traits with high genotypic coefficient of variability, heritability, genetic advance, and positive correlation coefficient and direct effect on seed yield can be recommended for further yield improvement at the respective location and at the national level in general.

Estimation of heritability and genetic variability in selected F1 bitter gourd population for yield and its contributing traits

Bitter gourd is one of the potential vegetables that has been clinically proven with several uses due to its medicinal advantages. However, it is less popular than other vegetable crops. Hence, this study was conducted to obtain detailed information on important agronomic traits and determine the pattern of inheritance of morphological traits in bitter gourd. Four F1 populations, P105 × P11, P11 × P92, P92 × P13 and P13 × P92 have been successfully generated from the hybridisation of four genotypes parental lines (P11, P13, P92 and P105). The result of analysis of variance showed that the parents and the F1 populations were significantly different (p < 0.01) in terms of vine length at 90 days after sowing, days of the first harvest after flowering, fruit number, fruit weight, fruit length, fruit girth, flesh thickness and total yield per plant. It also exhibited significantly different (p < 0.05) on days of to first male and female flower appearances. F1 progeny P11 × P92 recorded the highest total yield per plant (5376 g), followed by the parent P92 (4885 g). Positive and significant correlations were observed between total yield per plant and its contributing traits such as fruit weight (r = 0.81), fruit length (r = 0.73), flesh thickness (r = 0.65), fruit girth (r = 0.63), vine length at 90 days after sowing (r = 0.33) and fruit number (r = 0.27). This indicates a higher magnitude of variability for selection with a larger scope of a breeding program in future. The heritability (h 2 ) values ranged from 68.16% for the days of the first harvest after flowering to 99.81% for fruit weight. The highest value of genetic advance (GA) was recorded by the total yield per plant (3220.53%) while the lowest value was displayed by days of the first harvest after flowering (1.35%), respectively. High heritability and GA values indicated that some characteristics could be inherited by the next generation.

Selection of traits for seed yield improvement through variability parameters in sesame (Sesamum indicum L.) genotypes.

Sesame (Sesamum indicum L.) was renowned in the ancient ages for the stability of its healthy oil, accessibility of extraction, and drought resilience. Consequently, to produce novel varieties, the present work entails the utilization of basic metrics of variability and genetic variation. The investigation included 60 sesame genotypes and 13 quantitative characteristics. The analysis of variance revealed that genotypes were significant for all of the parameters assessed (P>0.05 and P>0.01). The average seed yield per plant was 6.93g, ranging from 4.84 to 9.17g. In all of the traits studied, the phenotypic coefficient of variation (PCV) was greater than the genotypic coefficient of variance (GCV). The tense relationship between PCV and GCV values indicated that the environment had minimal impact on the expression of the traits under investigation. The no. of branches, no. of capsules/axil, capsules per plant, no. of seeds per capsule, and oil content suggested higher estimations of PCV and GCV. The heritability varied from 75.13% for seed width to 99.03% for no. of capsules/axil. The genetic advance (GA) percent means varied from 7.71 (seed length) to 110.93 (no. of capsules/axil) at 5% selection intensity. plant height, no. of branches, 1000 seed weight, capsule length, capsules per plant, no. of seeds per capsule, seed thickness, oil content, and seed yield per plant all showed substantial heredity and a high GA% mean. Because of this, the traits of additive genetic control and direct selection in sesame have a high potential for increasing its yield.

Genotypic, phenotypic variability and evaluation of okra [Abelmoschus esculentus (L.) Moench] genotypes for yield components

Okra [Abelmoschus esculentus (L.) Moench] is India's major vegetable crop, accounting for 60% of exports. Comparatively, Tamil Nadu has a small area of cultivation and production. Hence, the present study involves the utilizatization of simple measure of variability and genetic variance to develop new varieties. The experiment was conducted with 60 genotypes of okra crop using 20 quantitative traits. The analysis of variance found that genotypes were significant (P 0.05 and P 0.01) for all of the traits tested. The fruit yield plant-1 ranged from 176.40 to 438.40 g, with 347.42 g being the average. In all the traits studied, the phenotypic coefficient of variation (PCV) was higher than genotypic coefficient of variation (GCV). The closeness of PCV and GCV values suggested that the environment had little influence on manifestation of the characters under examination. GCV (1.89-13.98) and PCV (4.06-16.61) levels were found to be moderate (10-20) and low (<10), respectively, in the study. Heritability ranged from 21.73 (days to first fruit harvest) to 97.19 (plant height) percent. At 5% selection intensity, the genetic advance (GA)% mean ranged from 1.82 (days to first fruit harvest) to 27.38 (plant height). Plant height (13.68, 13.48), internodal length (16.61, 13.98), first fruiting node (13.00, 10.89), number of fruits plant-1 (13.19, 11.91), number of marketable fruits plant-1 (13.36, 11.97) and fruit yield plant-1 (13.75, 12.29) showed high heritability and high GA% mean. Thus, the above-mentioned characteristics are additive genetic control and direct selection in okra has good potential for improvement in fruit yield.

Genetic variability of early flowering and yield contributing traits in Barnyard Millet [Echinochloa frumentacea (Roxb). Link] grown at different altitudes

Barnyard millet is an important up surging minor millet in Asia countries for food and nutritional security. Being a minorcrop, the genetics and inheritance of the traits need to understand, for effective utilization in the crop improvementprogrammes. Here, we investigated the genetic background and inheritance of different traits in barnyard millet genotypes.Forty germplasm accessions were evaluated in different ecological environments of southern India for 17 quantitative traits.Genetic variability analysis using GENSTAT and the pooled REML mean data results revealed that Phenotypic Co-efficientof Variation (PCV) was greater than the Genotypic Co-efficient of Variation (GCV) over the diverged ecological locationsindicating the existence of environmental influence on all the biometric traits studied. In the Western Ghats region (E1),high heritability coupled with high genetic advance was exhibited for traits like days to flowering, plant height, days tomaturity, number of nodes, length of nodes, number of basal tillers, stem diameter, flag leaf length, flag leaf width,inflorescence length, inflorescence width, length of peduncle, number of racemes, single ear head weight and grain yield perplant. Traits like thousand grain weight expressed moderate genetic advance with high heritability while, length of lowerracemes expressed moderate heritability with high genetic advance. Similarly, high heritability coupled with high geneticadvance was recorded for all the characters in valley region (E2) except thousand grain weight that showed high heritabilitybut moderate genetic advance. In contrast, in the area of plains (E3), all the traits exhibited high heritability coupled withhigh genetic advance. Since, majority of the traits have shown high heritability with high genetic advance, selection mightbe effective in these traits irrespective of the environment.

Breeding Potential of Some Exotic Tomato Lines: A Combined Study of Morphological Variability, Genetic Divergence, and Association of Traits

Tomato (Solanum lycopersicum L.) is called ‘the poor man’s orange’ due to its low price and improved nutritional values. An experiment was conducted to study the breeding potential of some exotic tomato lines by assessing various qualitative and quantitative traits conferring yield and quality attributes. Among the qualitative traits, greater variability was observed for growth type, stem hairiness, and fruit shape and size. A determinate growth habit was observed in the genotype AVTO9802 while the genotype AVTO0102 produced yellow color fruits. A significant (p ≤ 0.01) variation was also observed for the studied quantitative traits. Based on yield and traits attributed to yield, the genotypes AVTO0314, GPB0107, GPB0120 and AVTO9802 were selected as promising genotypes. The differences between the genotypic and phenotypic coefficients of variation (GCV and PCV) of the studied quantitative traits were very low. This suggests that the apparent variation was mainly due to the genotypes. The higher GCV and PCV values were observed for the number of primary branches plant−1 (NPB), number of fruits cluster−1 (NFC), individual fruit weight (IFW) and total soluble solids (TSS). High heritability was recorded for all quantitative traits in a broad sense. However, the individual fruit diameter showed the highest heritability (99.56). The highest (102.75) genetic advance (GA) was observed for the number of fruits plant−1 (NFP). High heritability coupled with high GA as percentage of mean were recorded for the traits NFP, NFC, fruit yield plant−1 (FYP) and IFW. FYP showed a significant positive correlation with NFC (0.714***) and a negative correlation with days to the first harvest (−0.539***) and plant height (−0.492**). Principal component analysis revealed that the first four components explained 78.5% of the total variation among the genotypes. Thus, the promising genotypes (AVTO0314, GPB0107, GPB0120, AVTO9802 and AVTO0102) isolated from this study can be used for developing high-yielding and high-quality tomato varieties.

GENETIC ANALYSIS OF QUALITATIVE AND QUANTITATIVE TRAITS AMONG PROGENIES OF ENSET CLONES ORIGINATED FROM SOUTHERN ETHIOPIA

<p>The present cultivated enset (<em>Ensete ventricosum</em>) clonal landraces in Ethiopia originated from few wild progenitors. However, enset has a mixed mode of reproduction in which, the wild enset reproduces sexually through seeds, while cultivated enset is generally propagated vegetatively. The objectives of this study were to determine the genetic structure of enset cultivars through genetic analysis of qualitative morphological traits and estimate their genetic variability by evaluating the quantitative agronomic traits data generated from progenies of cultivated and wild enset genotypes. Hence, seeds collected from six cultivated and four wild enset genotypes were used for this study. Data on four qualitative and six quantitative morphological traits were recorded from the progenies of the 10 enset genotypes. Progenies of seven enset genotypes segregated in a 3:1 segregation ratio while progenies of the remaining genotypes segregated differently for the qualitative traits considered. With regard to the quantitative traits, the progenies of the 10 enset genotypes differed significantly for five of the six traits except pseudostem length. The cultivated clones, in general performed better than that of the wild types. Moderate heritability (h2b) estimates and high genetic advances were obtained for leaf length (0.38, 62.0%), pseudostem circumference (0.35, 78.5%), and plant height (0.30, 19.1%) indicating selection for these traits indirectly improves economic yield of enset clones. This study demonstrated the possibility of creating genetic variation through selfing the existing enset genotypes for traits of interest and making improvements either through selection or crossing the elite types to develop novel enset cultivars.</p>

Studies on Genetic Architecture Through Variability Parameters and Association Analysis in Cowpea [Vigna Unguiculata (L.) Walp.

Genetic architecture through variability parameters and association analysis for green forage yield and its characters in 78 germplasm lines including 3 checks (MFC-8-14, UPC-5286 and TSFC-12-15) was carried out during Rabi 2015-2016. All the fifteen studied characters exhibited existence of variability significantly. This indicated existence of sufficient variability among the genotypes for the mentioned characters and sufficient scope for development of new variety or genotypes. High genetic advances as percentage of mean were recorded for green forage yield (q/ha/day). High heritability estimates were recorded for 100-seed weight (g) and by green forage yield (q/ha). Correlation coefficient showed significant positive correlation with dependent character green forage yield with green forage yield per day at genotypic and phenotypic level. Maximum positive direct effect was obtained for green forage yield per day. These results indicate that green forage yield can be improved much better way by selection. Selection for these traits is likely to accumulate more additive genes leading to further improvement of performance of genotypes. Bangladesh J. Bot. 50(3): 557-564, 2021 (September)

Genetic parameters, stability and selection of cassava genotypes between rainy and water stress conditions using AMMI, WAAS, BLUP and MTSI

An experiment was conducted with 25 cassava genotypes in Randomized Block Design with three replications in rainy seasons 2017−18 and 2018−19; water stress 2018−19 and 2019−20 to select the stable and superior genotypes that effectively tolerate water stress. AMMI ANOVA indicated significant G × E interaction for all the traits, Leaf Area Index (LAI), Yield per Plant (YPP), Harvest Index (HI), Dry Matter (DM) and Starch Yield per Plant (SYP). A high environment effect of 68.38 % of the total sum of squares was observed for DM followed by SYP, LAI, YPP and HI. A significant residual variation in G × E for YPP, HI and DM demonstrated that the presence of considerable noise in the model for these traits. Higher PCV and GCV values, moderate level of broad-sense heritability and high Genetic Advance as per cent of mean was observed for LAI, YPP and SYP indicating the possibility of high genetic gains for these traits through selection. CI-158 for LAI, CR43-11 for YPP, M4 for HI, Sree Pavitra and 9S127 for DM were identified as stable based on mean vs. WAAS biplot. Among all the environments, 8S501 and CR43-7 were ‘all-time winners’ for YPP. The rainy season and water stress were the two mega environments whose influence on traits was different. The accuracy of selection was very high for the traits HI followed by YPP and SYP. 8S501 followed by CR43-7 for YPP; 8S501 followed by CR43-7 for HI; 8S501 followed by Sree Athulya for DM; CI-130 followed by 8S501 for SYP had the highest predicted mean values. Based on MTSI, 8S501 followed by Sree Athulya, CR 43-7 and 9S127 were selected considering their mean performance and stability.

Genetic variability for Yield and Yield Related Traits in Orange-fleshed Sweetpotato Genotypes Evaluated at Hawassa, Ethiopia

The study was conducted to determine variability for yield and yield related traits in 24 orange fleshed sweetpotato [<i>Ipomoea batatas</i> (L.) Lam] genotypes in the 2017 main cropping season at Hawassa Agricultural Research Center. The experiment was laid out in a Randomized Complete Block Design with three replications. Data were collected on 19 traits and analysis of variance (ANOVA) was conducted. Significant differences (p≤0.05) among genotypes were observed for root yield and its components as well as morphological and qualitative traits including sweetpotato virus disease reaction (SPVD). The phenotypic coefficient of variation (PCV) ranged from 22.1% for mature leaf size to 118.3% for unmarketable root yield, while the genotypic coefficient of variation (GCV) ranged from 20.6% for root girth to 111.7% for unmarketable root yield. All the traits studied showed PCV and GCV more than 20%, suggesting high variability and this could be used for the selection of superior genotypes concerning character of interest. Most traits showed high values for broad-sense heritability, which ranged from 66.7 to 100%, indicating low environmental influence in the observed variation. High heritability coupled with high genetic advances as a percent of mean was observed for marketable root yield, root skin color, root beta carotene content, harvest index, vine length, vine inter-node length and above ground fresh weight, implying these characters are governed by additive gene action and selection would be rewarding for the further improvement of such traits.

Varietal evaluation of promising maize genotypes in mid hills of Nepal

The varietal evaluation of hybrid maize (Zea mays L.) genotypes with desired performance is one of the main objectives of maize breeding program. Fourteen hybrid maize genotypes were evaluated for 17 quantitative and nine qualitative traits in randomized complete block design with three replications at Sundarbazar, Lamjung, Nepal during May to September, 2019. The major objective was to identify superior genotypes based on genotypic and phenotypic variability, heritability, genetic advance, and correlation between grain yield and yield associated traits. We observed significant differences for 17 quantitative traits among the tested genotypes. Large variation was observed for grain yield among genotypes. Genotype RL-24-0/ RL-111 had the lowest yield (5.53 mt/ha) and Pioneer had the highest yield (11.98 mt/ha) whereas check variety Rampur Hybrid-10 yielded of 8.23 mt/ha. Grain yield showed highly significant positive correlations with stem girth (r= 0.67) and number of ears (r=0.6), but significant negative correlation with anthesis-silking interval (r= -0.55). The dendrogram grouped 14 genotypes into four clusters. Cluster I incorporated the highest number (five) of genotypes, which also had highest cluster mean (average yield of ~10 mt/ha) for grain yield. Traits namely test weight, ear aspect, anthesis-silking interval, number of ears, and tassel branching had high genotypic and phenotypic coefficient of variations, and heritability along with high genetic advances, indicating that these traits can be considered for maize breeding program.

Genetic Variation of Quantitative and Quality Traits in Rice Varieties

An investigation was carried out to study the genetic parameters and character association for yield, yield attributing, quality and nutritional traits of twelve rice varieties. Analysis of variance revealed significant differences for all the traits under study indicated the presence of wide genetic variability among the genotypes. Small differences between genotypic coefficient of variation and phenotypic coefficient of variation were recorded for all the characters studied which indicated less influence of environment on these characters. High heritability coupled with high genetic advance was observed for zinc content (brown) and number of chaffy grain per panicle exhibited, indicating that simple selection could be effective for improving these characters. Yield per hill had the highest positive direct effect. This study revealed that yield per hill, days to 50% flowering, days to maturity, panicle length and thousand grain weight are the most important yield contributing characters and an attempt should, therefore, be made for effective selection on these traits. Yield per hill might be considered as the most important trait due to low difference of GCV and PCV, high heritability in broad sense (h2b) with high genetic advance (GA) in percent of mean, significant positive correlation and high positive indirect effects. Another important trait such as days to 50% plants to flowering and thousand grain weight might also be considered due to their minimum difference of GCV and PCV values, high h2b with high GA in percent of mean, significant positive correlation and higher positive direct effects.&#x0D; Ann. Bangladesh Agric. (2019) 23(1) : 69-77

Selection Criteria and Selection Environment for Drought Tolerance of Egyptian Wheat (Triticum aestivum L.) Landraces

Strong correlations between wheat traits and drought tolerance (DT) associated with high heritability and high genetic advance from selection would allow plant breeder to use such traits as selection criteria. The objective of the present investigation was to determine the optimum selection criteria and selection environment for drought tolerance via estimation of correlation coefficients (r) among 13 agronomic, grain yield and quality traits and DT of 20 wheat landraces, broad-sense heritability (h2b) and genetic advance (GA) from selection for such traits under well-watered (WW) and water stressed (WS) environments. A two-year experiment was carried out using a split-plot design with four replications. Results concluded that the best selection criterion for drought tolerance in our study was grain yield/plant (GYPP), followed by a number of grains/spike (GPS), grain filling period (GFP), grain starch (GSC) and protein (GPC) content, plant height (PH) and days to maturity (DTM), since they showed high (r), high h2b and high GA estimates. The best selection environment was WW for days to anthesis, PH, spikes/plant, GPS, spikelets/spike, GYPP, GPC and WS for DTM, GFP, GSC and thousand-grain weight traits. This information could help future breeding programs in selection for improving drought tolerance of wheat.

Genetic Variability and Correlation Coefficients of Major Traits in Cold Tolerance Rice (Oriza sativa L.) Under Mountain Environment of Nepal

This study was conducted at Agricultural Research Station (ARS), Vijayanagar, Jumla Nepal comprising fifteen genotypes of cold tolerance rice during regular rice growing season of high hill in 2015 in RCBD (Randomized Complete Block Design) with three replications to observe genetic variability, correlation, heritability, genetic advance and clustering of genotypes in relation to yield and yield associated traits and selection and advancement of early maturing, high yielding, disease resistant, and cold tolerance genotypes for high mountain area. Analysis of variance revealed that all characters except number of panicle per hill were significantly different indicating presence of variation in genetic constituents. Phenotypic coefficient of variance (PCV) was higher than genotypic coefficient of variance (GCV) for all the corresponding traits under study indicating environmental influence for the expression of the traits. Higher PCV and GCV value were obtained in grain yield (Yld), number of grain per panicle (NGPP) and number of panicle per hill (NPPH). Higher heritability coupled with higher genetic advance (GA) was obtained in NGPP, NPPH and Yld, high heritability and medium GA was obtained in thousand grains wt (TGW), plant height (Pht) and panicle length (PL) indicating additive gene action indicating direct selection may be a tool for varietal development. Positive and significant correlation was obtained between all characters except DM and Pht, PL and PHT and TGW and PPH. Total three clusters were obtained in eighty percent euclidean similarity clustering indicating genetic closeness/distances among the genotypes. Culture 1 carries the superior five genotypes including NR-10638-B-B-4 and NR-10695-B-B-B.&#x0D; Int. J. Appl. Sci. Biotechnol. Vol 7(4): 445-452

Genetic variability of some Lilium longiflorum cultivars in Indonesia

Lilium longiflorum has various local cultivars dispersed throughout Indonesia. The objective of this study was to evaluate vegetative and floral traits and to observe genetic variability of those traits. The evaluation was conducted in a field trial at the Indonesian Ornamental Crops Research Institute (IOCRI) during 2015-2016. The experiment was arranged by randomized complete block design with three replications. Seven cultivars of Lilium longiflorum (‘Cipanas’, ‘Sukabumi’, ‘Parompong’, ‘Berastagi’, ‘Bali’, ‘Tomohon’ and ‘Japan’) were collected and their vegetative and floral traits were evaluated. The results showed that ‘Cipanas’, ‘Sukabumi’ and ‘Bali’ had the earliest flowering time (FT) (80-86 days) and ‘Japan’ showed the latest FT. ‘Berastagi’ produced maximum flower diameter (FD) and medium FT and plant height (PH). All characters except FD exhibited narrow genetic coefficient of variation (GCV) but wide phenotypic coefficient of variation (PCV). High heritability value (HV) estimation and high genetic advance (GA) estimation were observed for characters including PH, number of leaves, stem diameter, FT and number of flowers. FD trait was recorded and showed high values of GCV and PCV, high HV but low GA. Selection on the basis of this trait would be more effective on the early generations. Consequently, direct selection of local L. longiflorum in IOCRI will be based on FD improvement. Nevertheless, there were no correlation between FD and others traits.