Yield Component Traits Research Articles

Genetic monitoring of Indian rice (Oryza sativa) cultivars over decadal periods employing gene-specific markers and yield component traits

Context Regular genetic monitoring of rice diversity provides informed direction for plant breeders when selecting parents in breeding programs. Aims The investigation was conducted to assess the trends of decade-wise genetic diversity in popular Indian rice (Oryza sativa L.) genotypes. Methods We screened 62 genotypes including popular rice varieties released from the 1970s to 2010s in India along with landraces, using gene-specific markers and some of the key yield and yield-contributing traits. Key results Using gene-specific markers, genetic diversity has shown a downward trend from landraces to the 2010s. Qualitative analysis revealed that more alleles were present in landraces than released varieties. The disappearance of alleles was prominently observed in varieties released in the 1970s and even more so in the 2010s, which suggests that present-day cultivars are losing several valuable alleles of the key yield genes. Genetic diversity assessed using phenotypic data also exhibited a downward trend towards the 2010s. Molecular and phenotypic data on genetic diversity were used to group the rice genotypes, revealing that genotypes with common parents grouped together. Conclusions Genetic diversity has shown a downward trend from landraces to the 2010s, as assessed using both gene-specific markers and phenotypic data, although with slight deviations among various decades. Implications This study reinforces the fact that assessment of temporal trends in genetic diversity at regular intervals is warranted to meet future food demands while conserving on-farm crop diversity.

Phenotypic and genotypic association of yield and yield-related traits in eggplant (Solanum melongena L.) evaluated for two seasons

Research on phenotypic and genotypic and associations between traits of eggplants provide valuable insights into the intricate dynamics of breeding programs. By understanding the relationships between different traits, breeders can effectively plan, evaluate, and establish selection criteria to cultivate desired characteristics in eggplant. The aim of this experiment was to determine the correlation coefficients, both phenotypic and genotypic, among various characters related to yield and to analyse the direct and indirect effects of these traits on yield per plant using path analysis. A randomized complete block design (RCBD) was used to arrange the plants and replicated three times. The results across the seasons indicated significant variations (p≤0.05) of all the traits examined. Research on correlation has indicated a significant and strong relationship between the main traits that contribute to crop yield (fruit length and fruit weight) at both the phenotypic and genotypic levels. Furthermore, several traits including the number of fruits, fruit weight, fruit length, stomata conductance, transpiration rate, and photosynthetic rate have demonstrated a significant and positive correlation with yield per plant. These traits have also exhibited a direct influence on yield. Conversely, traits such as fruit diameter and stomata conductance have displayed a strong and positive indirect impact on yield through their influence on fruit weight, number of fruits, and number of branches. In tropical conditions, the variables of yield component and physiological traits have been found to be positively correlated with higher eggplant yields. Consequently, these variables can serve as reliable indicators for indirect selection for yield in eggplant cultivation.

Genetic analysis for detection of genes associated to drought tolerance in rice accessions belonging to north east India.

The North East (NE) India is rich in biodiversity and also considered as the secondary centre for origin of rice. The NE rice accessions was characterized previously using genetic markers and morphological traits. Simultaneously, genome-wide association studies (GWAS) reveal significant marker-trait associations for the drought tolerance traits. The genetic diversity and population structure of 296 NE rice accessions were studied using 96,712 single nucleotide polymorphism (SNP) markers distributed across 12 chromosomes. The accessions were clustered into two major sub-groups (SG). A total of 91 accessions were assembled as SG1 and 114 accessions as SG2, while the remaining 91 were admixture genotypes. A total of 200 genotypes belonging to different groups were phenotyped for yield component traits under drought and control conditions. The GWAS was performed to identify significant marker-trait associations (MTAs). Consequently, 47 MTAs were detected under drought, exhibiting 0.02-9.95% of phenotypic variance (P.V.). Whereas 58 MTAs were discovered under control conditions, showing a 0.01-9.74% contribution to the phenotype. Through in-silico mining of QTLs, 2999 genes were identified. Among these; only 22 genes were directly associated with stress response. These QTLs/genes may be deployed for marker-assisted pyramiding to improve drought tolerance in popular drought susceptible rice varieties.

Estimation genetic action of heritability percentage and inbreeding depression of four hybrids maize by generation mean analysis

The current study aims of to estimate genetic action, heritability percentage in its broad and narrow sense and inbreeding depression resulting from inbreeding, using the generation mean analysis method to analyze the generation's means of hybrids maize that different in flowering time and maturity. The genetic action, that controls inheritance of the yield components traits to the selected inbred lines and their resulting hybrids using the generation mean analysis. Five pure inbred lines of maize (ZA17WR, Zi17WZ, ZM74, ZM19 and ZM49W3E) were selected from fifteen different inbred lines with flowering dates and maturity in the spring season 2019 and were crosses according to the research target

Genetics analysis, combining ability and heterosis of some yield and yield component traits in summer squash (Cucurbita pepo L.)

Genetics analysis, combining ability and heterosis of some yield and yield component traits in summer squash (Cucurbita pepo L.)

Relationships between Grain Weight and Other Yield Component Traits of Maize Varieties Exposed to Heat-Stress and Combined Heat- and Water-Stress Conditions

It is necessary to identify the appropriate traits that influence yield in a given environment as part of a breeding programme. The objective of this study was to identify the morphological traits that contribute to maize grain weight (GWt) under abiotic stress conditions. Three drought-tolerant maize varieties were grown under no-stress (NHWS), heat-stress (HS), and combined heat- and water-stress (CHWS) conditions. Data from 19 morphological traits were analysed. The correlation results revealed that eight traits consistently produced a significant positive relationship with GWt under the three growth conditions. The path coefficient analysis revealed that in the NHWS, HS, and CHWS conditions, five traits consistently had a positive direct effect on the GWt. Given the magnitude of the positive direct effects, increasing dry biomass yield, harvest index, and grain number in the NHWS; grain number, harvest index, and ear width in the HS; and harvest index, days till silk appearance, leaf chlorophyll content, and grain number in the CHWS will increase GWt. Under various abiotic stress conditions, maize phenotypic expression varied. Therefore, the identified traits that contributed positively to GWt under various stress conditions should be considered when developing a maize improvement programme in a stress-prone environment.

Studies of genetic variability, heritability and genetic advance in yield component traits in bread wheat (Triticum aestivum L.)

Studies of genetic variability, heritability and genetic advance in yield component traits in bread wheat (Triticum aestivum L.)

Primordial initiation, yield and yield component traits of two genotypes of oyster mushroom (Pleurotus spp.) as affected by various rates of lime

Mushrooms are fleshy fungi valued globally for their nutritional and medical benefits. The study was conducted at Ebonyi State University Mushroom Center, Abakaliki, to determine an optimum level of limestone (CaCO3) on the genotypes for maximum growth and yield. The experiment was carried out as a split-plot experiment in a completely randomized design (CRD) with the use of Oyster mushroom variety. The two genotypes (GI and GII) were placed in the whole plot while limestone was placed in the sub-plot which consisted of five rates of CaCO3(Og,5 g, 10 g, 15 g and 20 g). Sawdust and rice husk substrates were used at the ratio of 60:40 and sterilized for six hours at 121 °C using the steam sterilization cylinder. The media bags were off–loaded after one day and allowed to further cool for another day before inoculation. The cultured spawn was used to inoculate the media upon cooling at room temperature. Data were collected on agro-morphological parameters such as primordial initiation, stalk height, stalk diameter, number of branches, number of fruits, number of productive bags, fresh and dry weights, and subjected to analysis of variance (ANOVA). The result obtained indicated that there was a significant difference (P < 0.05) between the two genotypes studied in all parameters except the dry weight of the mushroom. Also, the various rates of CaCO3 had a significant difference (P < 0.05) in most agro-morphological traits except stalk diameter, number of fruits and fresh weight. However, the interaction of the whole plot (genotype) and sub-plot (lime rates) showed no significant difference (P > 0.05) in all parameters evaluated except the stalk diameter. Genotype I initiated more primordial compared to primordial initiation in genotype II and they differed significantly (p < 0.05) from each other. More so, the result showed that increasing the rate of CaCO3 from 0 to 5 g significantly increased the primordial initiation from 17 to 22. However, further increase in lime rates above 5 g significantly reduced the primordial initiation from 22 to 15. It was concluded that the 5 g rate of limestone produced the best primordial initiation. Therefore, genotype I and 5 g of CaCO3 were recommended. There was also a strong relationship between the primordial initiation and most growth and yield components traits studied. There was a significant positive correlation between primordial initiation and stalk height (r = 0.799*), stalk diameter (r = 0.692*), number of mushroom branches (r = 0.773*), number of productive bags (r = 0.888*), number of fruits (r = 0.810*), fruit weight (r = 0.918*) and dry weight (r = 0.916*). Ideal conditions that would guarantee more primordial initiation for higher yield were recommended.

Discovering favorable genes, QTLs, and genotypes as a genetic resource for sesame (Sesamum indicum L.) improvement.

Sesame (Sesamum indicum L.) is an ancient diploid oilseed crop with high oil content, quality protein, and antioxidant characteristics that is produced in many countries worldwide. The genes, QTLs, and genetic resources of sesame are utilized by sesame researchers and growers. Researchers have identified the many useful traits of this crop, which are available on different platforms. The genes, genotypes, QTLs, and other genetic diversity data of sesame have been collected and stored in more than nine genomic resources, and five sesame crop marker databases are available online. However, data on phenotypic and genotypic variability, which would contribute to sesame improvements, are limited and not yet accessible. The present study comprehensively reviewed more than 110 original published research papers and scientifically incorporated the results. The candidate genes, genotypes, and QTLs of significantly important traits of sesame were identified. Genetic resources related to grain yield and yield component traits, oil content and quality, drought tolerance, salt tolerance, waterlogging resistance, disease resistance, mineral nutrient, capsule shattering resistance, and other agronomic important traits of sesame were studied. Numerous candidate genotypes, genes, QTLs, and alleles associated with those traits were summarized and discovered. The chromosome regions and linkage groups, maps associated with the best traits, and candidate genes were also included. The variability presented in this paper combined with sesame genetic information will help inform further sesame improvement.

Heterotic affinity and genetic control of monoecious cucumber (Cucumis sativus L.) inbred line for economic traits and tolerance to downy mildew disease

A cucumber (Cucumis sativus L.) hybrid could be acceptable to growers of tropical and subtropical climates if it is a high yielder with good fruit quality, and has appreciable tolerance against downy mildew disease which causes significant crop loss. Seven diverse parents were crossed in half diallel fashion to determine the extent of heterobeltiosis, mode of gene action, and combining ability effects for 17 quantitative characters at Research Farm, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, Nasia, West Bengal. Preponderance of non-additive gene action as realized from the predictability ratio for all the characters under study suggested heterosis breeding could be the best strategy to improve the yield and other component traits. On the basis of GCA effects and per se performance, two parents, BCCU-3 and BCCU-12 appeared consistently superior in respect of fruit yield/plant and other important horticultural traits including tolerance against downy mildew, and could be used as potential donors in future breeding. Outstanding hybrids based on SCA effects, heterobeltiosis manifested in them and per se performances were BCCU-16 × BCCU-4 and BCCU-3 × BCCU-16, and they could be commercially exploited after critical evaluations in tropics and subtropics. Commercially exploitable cucumber hybrids tolerant to downy mildew disease could be developed with the involvement of a single parent tolerant to this disease.

Mapping and identification of quantitative trait loci controlling test weight and seed yield of pearl millet in multi agro-climatic zones of India

Pearl millet [ Pennisetum glaucum (L.) R. Br.] is a climate-resilient nutri-cereal and is a staple food for the inhabitants of arid and semi-arid regions of the world. Yield stability is a major problem and requires exploiting key breeding strategies for the improvement of yield component traits in pearl millet. The main objective of the present study was the genomic dissection of yield and its component traits by identifying multi-environmental QTL in order to increase the efficiency and accuracy of pearl millet breeding. An experiment was designed for mapping agronomically important traits in 210 Recombinant inbred lines (RIL) derived from the cross PPMI 683 × PPMI 627. These RILs were evaluated in three diverse pearl millet growing regions in India for three consecutive years. Over the consecutive years and locations, thousand seed weight (TSW) showed a significant positive association with other agronomic traits. QTL analysis revealed three significant common QTL for TSW. the flanking markers of common QTL were Xpsmp2273- Xipes0203; Xpsmp2077- Xpsmp2059 and ICMP3058- Xipes0147 . The identified common QTL markers explained the total phenotypic variance of 27.57, 22.61,7.59% for QTL 1 on LG 1; 21.38, 24.13,12.14% for QTL 2 on LG 2, and 7.34, 15.26, 9.6% for QTL 3 on LG 6 across three consecutive years (2014–2016) at Delhi (E1), Dharwad (E2) and Jodhpur (E3), respectively. Two constitutive expressing QTL markers for Seed Yield per Plant (SYPP) were found at a significant threshold LOD value of 3.5 and flanked by the markers: Xpsmp2273- Xipes0203 and Xpsmp2077- Xpsmp2059 with a total phenotypic variance of 28.24 , 19.95%, and 6.31% for QTL 1 on LG 1; 19.78, 21.38, 7.17% for QTL 2 on LG 2 across consecutive years at Delhi, Dharwad and Jodhpur, respectively. In total, 34 and 29 significant digenic interactions were detected for TSW and SYPP, respectively. In the present study, using quantitative genetic variation for TSW and SYPP, major and stable QTLs were found across environments. Some potential genes that may affect the traits were identified in the comparative genomics scan using rice and Arabidopsis. Three significant and stable QTLs for TSW and two for SYPP were detected across all environments. The digenic interactions were detected for TSW (34) and SYPP (29) at Delhi, Dharwad, and Jodhpur. The mapped QTL for TSW and SYPP in the current study could be exploited to develop elite hybrid parental genotypes/cultivars through marker-assisted selection and genomic selection in breeding programs. • In an era of climate change, pearl millet has promising prospects to achieve economic returns. • Major and stable QTLs for TSW (3 QTLs) and SYPP (2 QTLs) were detected across the environments. • Two genomic regions with pleiotropic effects for TSW and SYPP at Delhi, Dharwad, and Jodhpur were detected. • Digenic interactions were detected for TSW (34) and SYPP (29) at Delhi, Dharwad, and Jodhpur. • All favorable QTLs to break down genetic barriers to yield for sustainable food security.

Molecular mapping of drought-responsive QTLs during the reproductive stage of rice using a GBS (genotyping-by-sequencing) based SNP linkage map.

In rice, drought stress at reproductive stage drastically reduces yield, which in turn hampers farmer's efforts towards crop production. The majority of the rice varieties have resistance genes against several abiotic and biotic stresses. Therefore, the traditional landraces were studied to identify QTLs/candidate genes associated with drought tolerance. A high-density SNP-based genetic map was constructed using a Genotyping-by-sequencing (GBS) approach. The recombinant inbred lines (RILs) derived from crossing 'Banglami × Ranjit' were used for QTL analysis. A total map length of 1306.424cM was constructed, which had an average inter-marker distance of 0.281cM. The phenotypic evaluation of F6 and F7 RILs were performed under drought stress and control conditions. A total of 42 QTLs were identified under drought stress and control conditions for yield component traits explaining 1.95-13.36% of the total phenotypic variance (PVE). Among these, 19 QTLs were identified under drought stress conditions, whereas 23 QTLs were located under control conditions. A total of 4 QTLs explained a PVE ≥ 10% which are considered as the major QTLs. Moreover, bioinformatics analysis revealed the presence of 6 candidate genes, which showed differential expression under drought and control conditions. These QTLs/genes may be deployed for marker-assisted pyramiding to improve drought tolerance in the existing rice varieties.

The interaction between drought stress and nodule formation under multiple environments in chickpea.

Environmental stresses, particularly drought, limit symbiotic nitrogen fixation in legumes, resulting in decreased yielding capacity. Drought is one of the most important constraints limiting yield potential in crops and it is the major abiotic stress that can cause more than 70% yield loss in chickpea. In this study, a total of two hundred four chickpea (Cicer arietinum L.) genotypes were selected to study the interaction between drought stress and nodule formation. This interaction was assessed by using morphological, yield and yield components. The field experiments were laid out in two locations (Terbol and Kfardan stations, Bekaa valley, Lebanon) using Alpha lattice design with two replications and two watering treatments (irrigation and rainfed) during 2016 and 2017 seasons. Parameters that were measured include days to 50% flowering (DFL), day to maturity (DM), plant height (PLH), nodule biomass (NB), nodule fresh weight (NFW), nodule dry weight (NDW), grain yield (GY), Biological yield (BY), 100 seed weight (100SW) and drought tolerance stress (DTS). The results indicated a significant variation between genotypes, environments and other morphological, yield and yield components traits. Drought stress reduced significantly the yield and the nodule’s characteristics, biological and grain yield. The genotypes with the highest levels of drought tolerance, such as IG70399, IG8256, IG71832, IG70270, and IG70272, showed a minimal decrease in yield and nodule biomass. Nodule observations significantly and positively correlated with GY (0.36-0.38) under drought stress treatment. The correlation values for nodule characteristics with DFL and DM were higher under drought stress compared to irrigated conditions. This is a comparative study between drought stress and nodule formation traits associated with morphological, yield and yield components traits.

Identification and validation of stable quantitative trait loci for yield component traits in wheat

Grain weight and grain number are important yield component traits in wheat and identification of underlying genetic loci is helpful for improving yield. Here, we identified eight stable quantitative trait loci (QTL) for yield component traits, including five loci for thousand grain weight (TGW) and three for grain number per spike (GNS) in a recombinant inbred line population derived from cross Yangxiaomai/Zhongyou 9507 across four environments. Since grain size is a major determinant of grain weight, we also mapped QTL for grain length (GL) and grain width (GW). QTGW.caas-2D, QTGW.caas-3B, QTGW.caas-5A and QTGW.caas-7A.2 for TGW co-located with those for grain size. QTGW.caas-2D also had a consistent genetic position with QGNS.caas-2D, suggesting that the pleiotropic locus is a modulator of trade-off effect between TGW and GNS. Sequencing and linkage mapping showed that TaGL3-5A and WAPO-A1 were candidate genes of QTGW.caas-5A and QTGW.caas-7A.2, respectively. We developed Kompetitive allele specific PCR (KASP) markers linked with the stable QTL for yield component traits and validated their genetic effects in a diverse panel of wheat cultivars from the Huang-Huai River Valley region. KASP-based genotyping analysis further revealed that the superior alleles of all stable QTL for TGW but not GNS were subject to positive selection, indicating that yield improvement in the region largely depends on increased TGW. Comparative analyses with previous studies showed that most of the QTL could be detected in different genetic backgrounds, and QTGW.caas-7A.1 is likely a new QTL. These findings provide not only valuable genetic information for yield improvement but also useful tools for marker-assisted selection.

Genetic Mapping of Quantitative Trait Loci Associated with Plant Height and Yield Component Traits in a Wheat (Triticum aestivum L.) Doubled Haploid Population Derived from Tugela-DN × Elands

Grain yield is a quantitatively inherited complex trait that is strongly influenced by interacting genetic and environmental factors. The identification of major quantitative trait loci (QTL) for plant height (PH) and yield component traits (YCT) is important for improving yield potential through wheat breeding. We performed a QTL analysis for PH and YCT in the Tugela-DN × Elands doubled haploid (DH) population using a genotype-by-sequence single nucleotide polymorphism and a silicoDArT-based genetic map. Field trials were conducted under rain-fed conditions across five environments in the Free State Province of South Africa during the 2017–2018 and 2018–2019 cropping seasons. Analysis of variance revealed significant differences (p &lt; 0.001) among DH lines and the environments. However, for G × E interactions, significant differences (p &lt; 0.05) were only observed for spikelet number per spike. Broad-sense heritability estimates of all traits ranged between 0.44 and 0.81. Nine QTL, viz. QPh.sgi-6A.2 and QPh.sgi-4D for PH, QSl.sgi-6A.2 and QSl.sgi-7A for spike length, QGns.sgi-3B for grain number per spike (GNS), QGwps.sgi-7B for grain weight per spike (GWPS), QGw.sgi-2A and QGw.sgi-7A for grain width, and QGl.sgi-3B for grain length (GL), were identified on chromosomes 2A, 3B, 4D, 6A, 7A, and 7B, in two or more environments. Some of these QTL exhibited pleiotropic effects. The QPh.sgi-6A.2 QTL for PH and QGwps.sgi-7B for GWPS appear to be novel QTL, while the rest of the reported QTL validated previously identified QTL for PH and YCT. The study also reported a trade-off between GL and GNS. The findings of this study will be useful in elucidating the genetic architecture of yield component traits contributing to the development of new dryland wheat varieties with high and stable yield.

Multivariate analysis based prediction of phenotypic diversity associated with yield and yield component traits in germplasm lines of rice (Oryza sativa L.)

An investigation was conducted with 217 germplasm lines of rice to estimate potential variation among rice genotypes. Multivariate analyses viz., PCA and cluster analysis to assess genetic diversity were performed on seven agronomic traits. For the evaluated traits in the lines of germplasm, box plots and normal probability plots displayed substantial estimates of variability. PCA showed that PC1 and PC2 represented 46.15 per cent of variation. PC1 was responsible for the most variance (24%) for four characters, followed by PC2 (22.15%) for three parameters. Filled grain number per panicle, single plant yield, plant height and thousand grain weight were identified as vital traits contributing to variability. Based on agglomerative hierarchical cluster analysis, the germplasm lines were grouped into five clusters, which explained a lot of variation in the traits. The study identified that plant height and 1000 grain weight have the greatest impact on variation. The genotypes viz., WGL 1063, RNR 26085, OR 2511-3, Swarna, KNM 7123, WGL 1063, MGD-101, IVT MS-6130, IVT IM-4231, IVT IME-3948 and IVT NPT-6303 were found to be the best performing genotypes for the traits panicle length, plant height and single plant yield, which can be used in hybridisation programme to improve these traits. Keywords: Rice, Box plot, diversity, germplasm, principal components and variability

Combining abilities and genetic parameters for grain yield and some agronomic traits in maize (Zea mays L.)

BackgroundThe improvement of maize hybrids relies on significant genetic variability among the inbred lines used and the degree to which it is transferred to progeny. Understanding the genetic parameters and heritability of traits in every population is an essential precondition for selection program. This study was designed to estimate the magnitude of genetic parameters and heritability of traits in line × tester mating design. Fifteen yellow maize inbred lines derived from different sources were crossed with two lines as tester i.e., Gm-1001 and Gm-1002 in 2019 summer season. During 2020 season, the resulted 30 crosses along with check hybrid SC-168 were evaluated in a yield trial at two locations: Gemmeiza and Sids Agric. Res. Station.ResultsThe mean squares among two locations were highly significant for all studied traits except KR−1. The L1 and L3 had the best general combiners for GY ard fed−1. In addition, the T1 as a tester was a GCA effects good combiner for earliness, shorter plants and lower ear placement traits. While T2 was good combiner for grain yield and some of attributes. Crosses L5 × T1 and L7 × T2 had positive and significant SCA effects for grain yield. The GCA variances were higher than SCA variances for all studied traits except for ED trait, indicating that additive genetic variance played the major role than non-additive genetic variance in the inheritance of these traits. Generally, phenotypic coefficient of variability was higher than genotypic coefficient of variability for all studied traits, suggesting that there was an influence by environments in the expression of these traits. Recorded heritability percentage in broad sense ranged from low for (ear position%, no. of ears/100 plants, ear diameter and grain yield) traits, medium for (days to 50% silking, plant height, ear height and no. of kernels/row) traits to moderate high for ear length trait.ConclusionOur investigation concluded that most of the studied lines exhibited highly general combiners and the superior crosses were as a result of a good × good combiner for most of yield components traits.

Natural variation of main biochemical components, morphological and yield traits among a panel of 87 tea [Camellia sinensis (L.) O. Kuntze] cultivars

Many attentions have been previously focused to identify the multiple biochemical components related to tea quality and health benefits, however, the natural variation of biochemical components present in tea germplasm has not been adequately evaluated. In this study, the main biochemical components, leaf morphological and yield characteristics were evaluated for four rounds of tea leaves in a panel of 87 elite tea cultivars suitable for black, green, or oolong tea. Significant variations were observed among the tea cultivars, as well as seasonal differences in the levels of the free amino acid (FAA), caffeine (CAF), tea polyphenols (TP), water extract (WE) and TP to FAA ratio (TP/FAA). Results showed that the average levels of FAA showed a seasonal change, with the highest level of 4.0% in the 1st spring tea in the cultivars suitable for green tea and the lowest of 3.2% in summer tea in the cultivars suitable for black tea. The average CAF content was highest 3.2% in the cultivars suitable for oolong tea in the 1st spring and the lowest 2.5% in the cultivars suitable for green tea in summer. Limited seasonal and varietal variations were noticed in the average levels of WE among the three categories of tea. In addition, significant natural variation of the morphological characteristics, bud length varying from 2.5 cm to 8.7 cm, bud density from 190.3 buds · m-2 to 1 730.3 buds · m-2, mature leaves biomass from 128.4 kg · hm-2 to 2 888.4 kg · hm-2, and yield component traits of 100 buds (one bud with two leaves) dry weight from 3.7 g to 37.7 g, tea yield/round from 444.6 kg · hm-2 to 905.3 kg · hm-2, were observed. The aim of our evaluation was not only to identify the advantages of seasonal and clonal variations but also to provide a new viewpoint for their further application. Representative accessions were selected from the germplasm to promote the establishment of an inherent biochemical constituent expressing the quality of black, green, and oolong tea. The findings might be utilized to establish early selection criteria to enhance the tea breeding and production program.

Studies of Genetic Variability, Heritability and Genetic Advance in Yield Component Traits in Chickpea (Cicer arietinum L.)

Twenty diverse genotypes of chickpea including three checks viz., GNG 158, GNG 1488, PNG 469- checks, were carried out under Agriculture Research farm, Department of Genetics of Plant Breeding, Lovely Professional University, Phagwara (Punjab). This experiment was conducted in Randomized Block Design (RBD) with three replications, during rabi 2021-2022. To estimate genetic variability, heritability and genetic advance percent of the mean. analysis of variance for the design of experiments has been present for all the twelve traits The analysis of variance estimation demonstrated that the mean sum of squares attributed to genotypes were significant for all of the characters, suggesting that there was enough genetic diversity among the genotypes. The current study found that the Phenotypic Coefficient of Variation (PCV) was greater than the corresponding Genotypic Coefficient of Variation (GCV) for all traits, which could be attributed to genotype-environment interaction to some degree or another, explaining environmental factors influencing the expression of these characters. In the present study, moderate PCV, GCV were observed in No. of secondary branches per plant, 100 seed weight, No. of primary branches per plant, Harvest index, biological yield per plant, No. of pods per plant, Plant height and Seed yield per plant. Low value of PCV and GCV were recorded in No. of seeds per pod, protein content, Days to maturity and Days to 50% flowering, shows the magnitude of PCV and GCV were low and indicating limited scope for improvement. The genotypic correlation coefficient was higher in magnitude than their corresponding phenotypic one, indicating there by strong inherent association between different traits studied. The phenotypic expression of correlation was less due to multiple influences of environmental components in the view of correspondence selection on phenotypic basis would be effective.

Genetic Variability Analysis for Agro-morphological and Seed Yield Component traits of Soybean (Glycine max (L.) Merrill) Genotypes under Mid Hill Zone of Himachal Pradesh

Aim, Design and Methodology: A research with 21 soybean genotypes including three checks was carried out in kharif 2021 at Research Farm of Genetics and Plant Breeding, CSK HPKV Palampur to estimate the genetic variation, heritability and genetic advance for 13 agro-morphological &amp; seed yield component traits that can be used as selection criteria in breeding programmes. RBD design was used to set up the experiment with a plot size of 3 × 1.35=4.05 m2 and replicated three times.&#x0D; Results and Conclusion: The results of the analysis of variance revealed that the genotypes varied considerably for days to 50 percent flowering, days to 75 percent maturity, plant height (cm), number of nodes per plant, inter-nodal length (cm), number of branches per plant, number of pods per plant, pod length (cm), number of seeds per pod, seed yield per plant (g), 100-seed weight (g), biological yield per plant (g) and harvest index (%) showing the genetic divergence of the planting materials from one another. According to the estimates of genetic variability, the phenotypic coefficient of variation for all the traits were greater than the genotypic coefficient of variation explaining the important role played by environmental factors in the manifestation of the traits. Higher values of PCV coupled with moderate GCV values were detected for harvest index (27.93%, 11.84%) indicating the presence of sufficient genetic variation for selection in such traits. High heritability estimates along with high genetic advance (as percent of mean) were recorded for plant height and 100-seed weight which could be ascribed to predominance of additive gene action and high selective index and therefore, selection pressure could be applied profitably to such traits for genetic modification in soybean.