Genetic Analysis of Seed Yield and Its Contributing Traits and Pattern of Their Inheritance in Fieldpea (Pisum sativum L)

Verma

et al. 2019

IJARe

An experiment was conducted to determine the magnitude of genetic variability, heritability and genetic advance as per cent of mean among fifty-five genotypes of pea using eleven quantitative characters viz., days to 50% flowering, plant height, number of first fruiting node, length of first fruiting node, number of pods per plant, length of pod, width of pod, number of seeds per pods, green pod yield per plant, seed yield per plant and shell weight per plant. The results of ANOVA showed significant differences among the genotypes for all the characters indicating the existence of wide spectrum of variability among the genotypes. The phenotypic coefficient of variation (PCV) was quite higher than the corresponding genotypic coefficient of variation (GCV). High value of GCV and PCV was recorded for seed yield per plant, number of pods per plant, shell weight per plant, green pod yield per plant, plant height, length of first fruiting node and number of first fruiting node. All the characters showed high magnitude of heritability in broad sense (>60%) ranged from 83.91% (width of pod) to 98.84% (number of pods per plant). Further, high heritability coupled with high genetic advance as percentage of mean (>20%) was observed for all the characters except days to 50 % flowering suggesting that these characters are genetically controlled by additive (heritable) gene action and can be utilized for pea improvement through selection. The genotypes which showed superior results for the objectives under study were VRP-383, VRP-311, VRP-320 and Kashi Shakti and can be utilized for further breeding programme of pea.

Section: Resultssupporting

confidence: 92%

Genetic variability, heritability and genetic advance studies in pea (Pisum sativum L.) for quantitative characters

Verma

et al. 2019

IJARe

“…The literature on transgressive segregation in Pisum sativum is scanty. Many studies evaluated the genetic variability of different genotypes to select dissimilar genotypes as parental of crosses in pea breeding programs or determined heterosis as a way to predict transgressive segregants, the most recent ones being Khan et al (2016) and Kumar et al (2017). However, there are not many studies that identified transgressive segregants in the following generations, and this information is most relevant for the production of new cultivars.…”

Section: Discussionmentioning

confidence: 99%

“…(2016) and Kumar et al . (2017). However, there are not many studies that identified transgressive segregants in the following generations, and this information is most relevant for the production of new cultivars.…”

Section: Discussionmentioning

confidence: 99%

Transgressive Segregation, Heterosis and Heritability for Yield-Related Traits in a Segregating Population of Pisum Sativum L.

et al. 2018

SUMMARYPea is a self-pollinated, diploid (2n = 14), annual crop produced worldwide for human consumption and animal feed. The exploitation of maximum genetic potential from available pea resources implies the knowledge of genetic parameters of yield components. Hence, the present study was conducted in a cross between two pea varieties, namely DDR14 and Explorer, its F2 progeny and F3 families to find out transgressive segregants and to determine the magnitude of narrow sense heritability and heterosis. The high narrow sense heritability values obtained indicated that rapid gain could be achieved through selection for the different traits; however, the presence of genotype x environment interaction could limit the correspondence of these estimated values with the observed ones. The selection of lines through their phenotypic values is influenced by environmental and error effects. Best linear unbiased prediction (BLUP) was used for the prediction of genotypic values using morphological data from different years, allowing the correction for environmental effects. These estimates were used for genetic analysis of the traits. Heterosis was observed for number of pods (27.1%) and number of seeds (23.3%), characters that have a direct effect on yield. The cross also showed high frequency of transgressive segregation for these characters in F3 generation (15.5% and 13.6%, respectively). There were 12.73% families transgressive for two or more characters, with genotypic values of 49.82–64.41 for number of pods and 153.75–189.59 for seed number. The crossing between Explorer and DDR14 provided a base for the selection of superior progeny.

“…Both phenomena are predicted to produce more exaggerated hybrid phenotypes with increasingly divergent parental lineages (Guindon, Martin, Cravero, & Cointry, 2019). Furthermore, heterosis has been used in many studies to predict the successful establishment of transgressive phenotypes in subsequent generations (Chahota, Kishore, Dhiman, Sharma, & Sharma, 2007;Guindon et al, 2019;Khan, Mahbub, Reza, Shirazy, & Mahmud, 2016;Kumar, Jeberson, Singh, & Sharma, 2017). These studies of agricultural crops highlight the importance of examining trait values in the F1 hybrid stage to make meaningful predictions about long-term success.…”

Section: Transgressive Hybrid Phenotypesmentioning

confidence: 99%

Allele specific expression and gene regulation explain transgressive thermal tolerance in non-native hybrids of the endangered California tiger salamander (Ambystoma californiense)

Cooper

Shaffer

2019

Preprint

Hybridization between native and non-native species is an ongoing global conservation threat. Hybrids that exhibit traits and tolerances that surpass parental values are of particular concern, given their ability to outcompete the native parent. It is crucial to understand the mechanisms that drive these transgressive hybrid traits to diagnose and develop strategies to manage hybrid populations. Here, we explore several aspects of the hybridization between the endangered California tiger salamander (Ambystoma californiense; CTS) and the introduced barred tiger salamander (Ambystoma mavortium; BTS). We assayed critical thermal maximum (CTMax) to compare the ability of CTS, BTS and hybrids to tolerate acute thermal stress, and found that hybrids exhibit a wide range of CTMax values, with 40% (6/15) able to tolerate temperatures greater than either parent. We quantified the genomic response of each individual to discover and compare thermal abatement strategies. We found that CTS and BTS have strikingly different numbers and tissue-specific patterns of overall gene expression, with hybrids expressing intermediate values. We evaluated transgressive and variable phenotypes by uncovering regulatory mechanisms that give rise to these unique traits. F1 hybrids display abundant and variable degrees of allele specific expression (ASE), likely arising from extensive compensatory evolution in gene regulatory mechanisms of the parental lineages. We found that the proportion of genes with allelic imbalance in individual hybrids correlates with their CTMax, suggesting that BTS-biased expression confers improved thermal tolerance. We discuss the implications of these findings with respect to ongoing management of CTS in the face of future climate change.