scholarly journals Gene Action Studies in Cowpea Inbreds and Hybrids with Varying Levels of Heterosis

Author(s):  
B. Lovely ◽  
V. Kumar

Background: Cowpea is an important pulse crop grown worldwide that fits well in a variety of cropping systems. Improvement in yield and related characters along with reduced duration are desirable traits in this crop. The study of heterosis reveals the type of gene action involved which enables the plant breeder to adopt suitable breeding methodology for its improvement. Methods: The present investigation was carried out with 10 parent partial diallel design to analyse the gene action and estimate of heterosis with respect to nine yield related traits in cowpea.Result: Highly significant variances observed for all the traits indicated that hybrids and parents were different from each other for the traits under study and that variability in the breeding materials was attributed to additive and non-additive gene effects. Perusal of the data revealed significant positive heterosis for all yield related traits and significant negative heterosis for days to 50% flowering indicating earliness. Among the twenty five crosses studied, VS9 x VS43, VS24 x VS45 and VS44 x VS47 had significant heterosis for maximum number of characters. Both gca and sca variances were significant for all the characters indicating both additive and non-additive gene actions controlling the various traits. The additive variance was much higher than dominance variance for the characters days to 50% flowering, pod length, pod breadth, pod weight, pods per plant and cluster, pod yield per plant, seeds per plant and length of harvest period suggesting the preponderance of additive gene action.

Author(s):  
G. Thamodharan ◽  
A. Ramalingam ◽  
S. Geetha

An experiment was carried out in blackgram using line x tester mating design to estimate the gca effect of parents (six lines and five testers) and sca effect of 30 hybrids for yield and its traits. Estimates of gca and sca variances, degree of dominance, predictability ratio and narrow sense heritability revealed that only three trais viz., pods per plant, seeds per pod and single plant yield were controlled by additive gene action and hence showed high narrow sense heritability. Magnitude of non-additive gene action was higher than the additive gene action for traits like plant height, days to 50% flowering, cluster per plant, 100 seed weight, days to maturity, branches per plant and pod length. Three parents ‘MDU1, ADT3 and LBG-752 were the best combiners and three crosses ‘MDU1 x VBN (Bg) 6, LBG-752 x VBN (Bg) 6, LBG-752 x Mash-114 showed high per se performance and significant positive sca for yield. For exploiting both additive and non-additive gene action recurrent selection to be followed to improve yield in blackgram.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mandakini Kabi ◽  
Bhabendra Baisakh ◽  
Manasi Dash ◽  
Swapan K Tripathy ◽  
S. Sahu ◽  
...  

The study of gene action and combining ability have been conducted in 28 F1 cross combinations along with eight parents in 8x8 half-diallel scheme following Griffing’s Approach for 14 morphoeconomic traits including seed yield and oil content in sesame. The general combining ability (GCA) and specific combining ability (SCA) component of variation were significant for parents and crosses respectively for all characters except internode length for GCA indicating role of both additive and nonadditive gene action. However, higher proportion of SCA variance (?2 sca) than GCA variance (?2 gca) revealed preponderance of non-additive gene action for all characters except capsule length and capsule width under study. Further, variance due to dominance played a significant role than additive variance in all traits except capsule width and 100-seed weight. Nirmala is considered as the best general combiner owing to its higher estimate of gca effects for yield per plant, for days to maturity, plant height, branches per plant, capsules per plant, seeds per capsule, capsule length and 100-seed weight. Among cross combinations; Rama × GT-10, AT-382 × Krishna, AT-382 × Nirmala, Krishna × Nirmala, Krishna × Uma, Nirmala × Prachi and Prachi × Uma showed significantly higher sca effect for seed yield per plant in the desired direction indicating their merit for recovery of transgressive segregants for higher productivity following reciprocal recurrent selection.


Author(s):  
Alireza Haghighi Hasanalideh ◽  
Mehrzad Allahgholipour ◽  
Ezatollah Farshadfar

This study was undertaken to assess the combining ability of 6 rice varieties, for viscosity parameters and determining gene action controlling Rapid Visco Analyser (RVA) characters. F2 progenies derived from a 6×6 half diallel mating design with their parents were grown in a randomized complete block design with three replications at the research farm of Rice Research Institute of Iran (RRII) in 2015. The diallel analysis by Griffing`s method indicated the involvement of additive and non-additive gene actions controlling RVA traits. For traits PV and FV RI18447-2 and IR50 were the best combiners for increasing and decreasing, respectively. Deylamani and IR50 were the best combiners for increasing and decreasing BV, respectively. Beside, due to more portion of non-additive gene action in controlling trait SV, The Gilaneh × RI18430-46, and Deylamani × RI18430-46 crosses were the best for increasing and decreasing SV, respectively. The high estimates of broad sense heritability and narrow sense heritability for BV and FV, indicated the importance of additive effects in expression of these traits. Therefore, selection base breeding methods will be useful to improve these traits and selection in the early generations could be done to fix the favourable genes. Low estimate of narrow sense heritability for SV revealed that non-additive gene effects play important role in controlling setback viscosity. So, hybrid base breeding methods will be useful to improve this trait.


2007 ◽  
Vol 20 (2) ◽  
pp. 23-30 ◽  
Author(s):  
Z. I. Sarker ◽  
A. K. M. Shamsuddin ◽  
R. Ara

Estimates of gene action for lodging related traits at Wheat Research Center during 1999-2002 in three crosses of wheat showed different genetic control of the traits among the crosses. For almost all traits, additive or dominance effects or both components were significant in either three- or six-parameter model, indicating that both additive and dominance gene effects were operative for different traits contributing to lodging resistance. Although duplicate type of epistasis was also observed for second internode breaking strength, plant height and spikes per plant and grain yield per plant once in different crosses, additive x additive epistasis along with additive gene action for the aforesaid traits would improve selection of the same in the segregating populations. The additive x dominance gene interaction for second internode length, diameter and wall thickness would be useful too for improvement of second internode breaking strength and consequently lodging resistance, as their inheritance and selection in segregating populations would be relatively easier than the traits controlled by completely non-additive genes. For duplicate type of epistasis biparental mating or recurrent selection followed by conventional selection is suggested.DOI: http://dx.doi.org/10.3329/bjpbg.v20i2.17031


2016 ◽  
Vol 8 (11) ◽  
pp. 138 ◽  
Author(s):  
Lawrence Owere ◽  
Pangirayi Tongoona ◽  
John Derera ◽  
Nelson Wanyera

<p>Blast disease is the most important biotic constraint to finger millet production. Therefore disease resistant varieties are required. However, there is limited information on combining ability for resistance and indeed other agronomic traits of the germplasm in Uganda. This study was carried out to estimate the combining ability and gene effects controlling blast disease resistance and selected agronomic traits in finger millet. Thirty six crosses were generated from a 9 × 9 half diallel mating design. The seed from the 36 F<sub>1</sub> crosses were advanced by selfing and the F<sub>2</sub> families and their parents were evaluated in three replications. General combining ability (GCA) for head blast resistance and the other agronomic traits were all highly significant (p ≤ 0.01), whereas specific combining ability (SCA) was highly significant for all traits except grain yield and grain mass head<sup>-1</sup>. On partitioning the mean sum of squares, the GCA values ranged from 31.65% to 53.05% for head blast incidence and severity respectively, and 36.18% to 77.22% for the other agronomic traits measured. Additive gene effects were found to be predominant for head blast severity, days to 50% flowering, grain yield, number of productive tillers plant<sup>-1</sup>, grain mass head<sup>-1</sup>, plant height and panicle length. Non-additive gene action was predominant for number of fingers head<sup>-1</sup>, finger width and panicle width. The parents which contributed towards high yield were <em>Seremi 2</em>, <em>Achaki</em>, <em>Otunduru</em>, <em>Bulo</em> and <em>Amumwari</em>. Generally, highly significant additive gene action implied that progress would be made through selection whereas non-additive gene action could slow selection progress and indicated selection in the later generations.</p>


2018 ◽  
Vol 43 (4) ◽  
pp. 599-609
Author(s):  
ANMS Karim ◽  
S Ahmed ◽  
AH Akhi ◽  
MZA Talukder ◽  
A Karim

Combining ability effects were estimated for grain yield and some other important agronomic traits of maize in a 7×7 diallel analysis excluding reciprocals. The variances for general combining ability (GCA) were found significant for yield, days to pollen shedding, days to silking and ear height while it was found non-significant for plant height and number of kernels/ear. Non-significant general combining ability (GCA) variance for plant height and number of kernels/ear indicates that these two traits were predominantly controlled by non- additive type of gene action. Specific combining ability (SCA) was significant for all the characters except yield and days to silking. Non-significant specific combining ability (SCA) variance for yield and days to silking suggests that these two traits were predominantly controlled by additive type of gene action. Both GCA and SCA variances were found significant only in days to pollen shedding and ear height indicated the presence of additive as well as non additive gene effects for controlling the traits. However, relative magnitude of these variances indicated that additive gene effects were more prominent for all the characters studied except days to silking. Parent BIL95 was the best general combiner for both high yield and number of kernels/ear and parent BML4 for dwarf plant type. Two crosses (BML4× BML36 and BIL114× BIL31) exhibited significant and positive SCA effects for grain yield involved low × average and average × average general combining parents. The range of heterosis expressed by different crosses for grain yield and days to silking was from -65.83 to 21.26 percent and -17.85 to 8.22 percent, respectively.. The better performing three crosses (BIL114×BIL31, BIL138×BIL95 and BIL31×BIL95) can be utilized for developing high yielding hybrid varieties as well as for exploiting hybrid vigour.Bangladesh J. Agril. Res. 43(4): 599-609, December 2018


2016 ◽  
Vol 50 (3) ◽  
Author(s):  
R. S. Singh ◽  
M. N. Singh

The six generations (P<sub>1</sub>, P<sub>2</sub>, F<sub>1</sub>, F<sub>2</sub>, BC<sub>1</sub> and BC<sub>2</sub>) of twelve cross combinations of pigeonpea (<italic>Cajanus cajan</italic> L.) were studied during 2003-2006 for days to 50 % flowering, days to maturity, plant height, number of primary branches, number of secondary branches, pods per plant, pod length, number of seeds per pod, 100-seed weight, harvest index and seed yield per plant. The means of six generations were subjected to detect main gene effects and interactions. The estimates of six parameter model revealed that both additive and dominant gene effects were important in all the crosses for almost all the traits. However, the relative contribution of dominant gene effects was much higher than additive gene effects for plant height, pods per plant and seed yield per plant. Higher frequency of duplicate type of epistasis also confirms the prevalence of dominance gene effects for above traits except for seed yield per plant.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1172e-1172
Author(s):  
J. H. M. Barten ◽  
J. W. Scott ◽  
J. Elkind ◽  
N. Kedar

A half diallel including 11 parents was conducted under high temp. conditions in Florida and low temp. conditions in Israel. Blossom scar (BS) size was measured relative to the fruit size for 20 mature fruits per plot. Griffing's analysis showed that both GCA and SCA effects were highly significant at both locations (p< 0.0001). Analysis according to Hayman indicated no epistatic effects. In both environments, additive and dominant gene action was significant (p < 0.0005), although the additive gene effects were most important. Averaged over all loci, the incomplete dominance was in the direction of small BS. Narrow sense heritability estimates were 0.62 and 0.57 for Florida and Israel, respectively. Combined analysis showed that the genetic system was unstable over the 2 environments, as both additive and dominant gene effects interacted significantly with environment (p < 0.0001). The implication for breeding programs is that hybrid performance should be tested at several locations to insure stability of small BS.


2022 ◽  
pp. 1-10
Author(s):  
Rahul Chandel ◽  
A. T. Sadashiva ◽  
Kundapura V. Ravishankar ◽  
Anjan Das ◽  
Bichhinna Maitri Rout ◽  
...  

Abstract Tomato is a pivotal vegetable crop worldwide concerning human nutrition, economy and in service to biotechnology. Tomato leaf curl virus (ToLCV) is a begomovirus transmitted through the whitefly (Bemisia tabaci) and is responsible for severe losses in tomato production. In this context, the current investigation was carried out to determine heterotic combiners with high yield, resistance to ToLCV and mode of gene action for economically important traits. For this, 11 prescreened inbred lines were crossed in a half diallel fashion to generate 55 F1 hybrids. The 55 crosses with 11 parents and commercial checks were evaluated for different horticultural traits and resistance to ToLCV. The molecular validation with SCAR markers TG0302 and SCAR1 confirmed the presence of ToLCV-resistant genes in parents and their crosses. The hybrid IIHR-2902 × IIHR-2852 showed the presence of both Ty-2 and Ty-3 alleles in the homozygous state. The estimation of σSCA2 and σGCA2 was significant. It also indicated that the genetic control of target traits was under additive and non-additive gene effects. The values of σA/D2 along with σGCA2/σSCA2 found to be less than unity indicates the preponderance of non-additive gene action in the expression of the studied traits except for percent disease incidence. The parental line IIHR-2919 was the best combiner for fruit and yield traits. The cross combinations IIHR-2913 × IIHR-2898 exhibited significantly higher economic heterosis for yield along with the presence of Ty-2 and Ty-3 genes. The study paves the way for breeding high yielding and ToLCV-resistant hybrids in tomato.


Author(s):  
Akashi , , , , , Sarma ◽  
V. J. Dhole ◽  
A. Bhattacharjee ◽  
P. Das ◽  
D. Sarma ◽  
...  

Uniform and healthy seeds of green gram cv. Pratap (SG-1) were treated with two mutagens, gamma rays (physical mutagen) and EMS (chemical mutagen) alone and in combination. The two hundred forty M1 progenies were laid in randomized block design with three replications during Kharif, 2017 to raise M2 generation. Analysis of variance discloses significant differences among the treatments for all the eight characters studied. It was observed that in general, the combination dose, i.e., 200 Gy+0.2% EMS gave superior results in almost all the yield attributing characteristics. High heritability coupled with high genetic advance was recorded for seed yield per plant, which indicates the predominance of additive gene action. Number of pods per plant followed by pod length showed high significant positive correlation with seed yield per plant. The character number of pods per cluster had shown positive correlation with seed yield per plant, but path analysis revealed its negative direct effect on seed yield.


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