scholarly journals Genetics of angular leaf spot (ALS) resistance in South African market class dry bean (Phaseolus vulgaris) cultivars

2020 ◽  
pp. 1589-1594
Author(s):  
Josephine T. Pasipanodya ◽  
Rob Melis ◽  
Deidre Fourie

Angular leaf spot (ALS) caused by Pseudocercospora griseola (Sacc.) is one of the serious fungal diseases affecting dry bean in Africa, including South Africa. Host plant resistance is the best management strategy, of which its effectiveness requires knowledge of the genetics underlying the resistance in guiding breeding efforts. In this study, the inheritance of ALS resistance was studied through the generation mean analysis biometrical procedure. Six generations consisting of the two parents Ukulinga and Gadra, and its cross derived filial progenies (F1), second-generation (F2), and backcrosses of F1 to Ukulinga (BCP1) and Gadra (BCP2) were planted in a net-house and later inoculated using a mixture of P. griseola isolates. Leaf lesions (% disease severity) were rated using a CIAT 1-9 scale and analysed using SAS macros in Proc GLM of SAS version 9.3. Results of ANOVA for a full model displayed significant additive effects (P<0.05) and highly significant (P<0.001) additive x dominance effects. Segregation analysis indicated 9:7 ratio, implying the involvement of complementary gene effects. The number of genes was estimated to be 1.79; however, due to epistasis two or more genes possibly govern the resistance in this cross. Broad and narrow sense heritabilities were 0.40 and 0.33, respectively. Therefore, the estimated narrow-sense heritability, additive gene effects, and epistatic interaction imply that it is prudent to delay selections until later stages, in which homozygosity could be achieved and additive effects fixed.

1961 ◽  
Vol 57 (3) ◽  
pp. 289-294 ◽  
Author(s):  
S. R. Searle

Part of the variation among butterfat yields in dairy cows arises from genetic differences among the animals. The proportion which this bears to the total variance is known as heritability. In the ‘narrow’ sense it is defined (Lush, 1940), as the proportion of the total variance that is due to additive gene effects; the ‘broad’ sense definition includes genetic variation arising from non-additive gene effects as well as that due to additive effects. Since related animals have a proportion of their genes in common the covariance among their production records can be used for estimating genetic variation and hence heritability. This paper discusses three groups of related animals most frequently used for this purpose, twins, daughter-dam pairs and paternal half-sibs, and presents the results of analysing production records of artificially bred heifers in New Zealand, including evidence of the magnitude of the sampling errors of the heritability estimates.


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.


2016 ◽  
Vol 10 (11) ◽  
pp. 238-245 ◽  
Author(s):  
Amos Chilagane Luseko ◽  
Nchimbi-Msolla Susan ◽  
Mbogo Kusolwa Paul ◽  
Gabriel Porch Timothy ◽  
Miryam Serrato Diaz Luz ◽  
...  

Genetika ◽  
2015 ◽  
Vol 47 (2) ◽  
pp. 559-570 ◽  
Author(s):  
Mehrzad Allahgholipour ◽  
Ezatollah Farshdfar ◽  
Babak Rabiei

This study was conducted to determine the combining ability and heritability of rice grain yield, its components and some grain quality traits such as amylose content (AC), gelatinization temperature (GT), gel consistency (GC) and head rice recovery (HRR). The study was commenced by crossing the selected rice varieties based on a full diallel mating design. The F1 was harvested at the end of the season. In the following season, the crossed, reciprocal and parental lines were planted in randomly complete block design with three replications. Analysis of variance indicated that genotypes were significantly different for all traits. The diallel analysis by Griffing`s method showed highly significant differences for GCA for number of panicles per plant (PN), amylose content, gelatinization temperature and head rice recovery. Highly significant differences were also observed for both SCA and REC for all evaluated characters. The results showed that the grain yield (GY), number of filled grains (FGN), 100-grain weight (HGW) and GC were controlled by non-additive gene action, while the inheritance of PN, AC, GT and HRR were largely controlled by additive gene effects, although non- additive genetic components and reciprocal effect were also involved, which suggest that a selection process could be done in the early generations. The two improved lines (RI18442-1 and RI18430-46) were found to be good general combiners for GY and FGN, while the best combiners for PN was Tarom Mohali and IR50 and for HGW was RI18430-46. The best combinations for GY were RI18430-46 ? IR50, Tarom Mohali ? RI18447-2 and Daylamani ? RI18430-46. The good hybrids were Tarom Mohali ? IR50, Line23 ? RI18447-2 and Line23 ? Backcross line for AC. Narrow sense heritability showed that the GY and GC had the lowest values while the other traits had either moderate or high heritability, which indicates selection in the early generations could be done to fix the favorable genes. In present study, narrow sense heritability was high for AC and moderate for GT, PN and HRR.


2020 ◽  
Vol 100 (1) ◽  
pp. 1-15
Author(s):  
U. Subedi ◽  
S. Acharya ◽  
S. Chatterton ◽  
J. Thomas ◽  
D. Friebel

Cercospora leaf spot (CLS), caused by Cercospora traversoana, is an important phyto-pathological problem of self-pollinated fenugreek (Trigonella-foenum graecum). Developing resistant genotypes in crop plants has been considered the best option to control diseases for economic, environmental, and social reasons. However, before this can be accomplished, knowledge about the inheritance of disease-resistant genes is necessary for creating high-yielding resistant genotypes. One susceptible fenugreek cultivar, Tristar, and two resistant accessions L3717 and PI138687 were used in two-way crosses using hand emasculation and pollination technique in a greenhouse. F1 plants were grown in a greenhouse and allowed to grow till maturity to produce F2 seeds. Some flowers from F1 plants were crossed back to both resistant and susceptible parents separately to generate backcross (BC1) seeds. Parents, F1, F2, and BC1 populations were grown in the greenhouse using a RCBD with four replications. Plants were inoculated 30 d after sowing with a suspension of C. traversoana at 2 × 105 conidia mL−1. Symptoms were observed and rated on individual plants 25 d after inoculation, and plants were categorized according to susceptible or resistant reactions based on rating scores. Mean disease score was significantly different (p < 0.0001) among generations. In both the cross combinations, results showed CLS resistance in fenugreek (from L3717 and PI138687) was governed by a single dominant gene which is moderately heritable (46% narrow sense heritability). This indicates a relatively simple pathway for transfer of genes to adapted fenugreek cultivars.


2009 ◽  
Vol 168 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Mario C. N. Saparrat ◽  
Geraldine E. Fermoselle ◽  
Sebastián A. Stenglein ◽  
Mónica B. Aulicino ◽  
Pedro A. Balatti

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.


1975 ◽  
Vol 17 (4) ◽  
pp. 621-629 ◽  
Author(s):  
L. C. Ho ◽  
L. W. Kannenberg ◽  
R. B. Hunter

Pericarp thickness of 16 short-season inbred lines of corn (Zea mays L.) ranged from 35 to 126 μm with an overall mean of 82 ± 5 μm. The mode of inheritance of this trait was studied in two experiments. Two inbreds representing the extremes of pericarp thickness, their F1 and F2 generations, and both first generation backcrosses were included in Experiment 1. The inheritance of pericarp thickness proved to be quantitative in nature. All gene effects were significant, but epistatic effects, particularly dominance × dominance, were the largest in this particular cross. This could have resulted from bias due to linkage disequilibrium. Experiment 2 was a diallel set of 5 inbreds to include the parents and all possible single crosses, but not reciprocals. Diallel graphic analysis of these data indicated partial dominance for thin pericarp with minimal epistasis. Analysis II of Gardner and Eberhart showed that the mean square for line effects was several times larger than the heterosis estimates, indicating a high level of additive gene effects. The narrow sense heritability estimate was 72%. Thus selection for specific pericarp thickness should be effective and relatively rapid.


1985 ◽  
Vol 27 (5) ◽  
pp. 603-607 ◽  
Author(s):  
Anne L. McKendry ◽  
Peter B. E. McVetty ◽  
Harvey D. Voldeng

The inheritance of seed protein, seed oil, and the sum of protein and oil was investigated in two early maturing soybean crosses, 'Maple Presto' × 'Sioux' and 'Maple Presto' × X446-2-1, in 2 years (1981 and 1982) at one location (Winnipeg). Analyses of variance of the parental performance over years indicated that the parents differed significantly for all three traits studied and that genotype by year interactions were effectively zero. Generation means analysis indicated that gene action for seed protein was primarily additive, with partial dominance for low protein. Seed oil was also conditioned primarily by additive gene action. Partial dominance was not consistently detected over years and therefore was of minor importance. Additive × additive epistatic effects for seed oil were also detected but were not consistent over years. The sum of seed protein and oil was conditioned solely by additive gene action. Variance analyses indicated a predominance of additive genetic variance for all three traits. Dominance variance was also detected for both seed protein and the sum of protein and oil. Broad sense heritability for the F2 generation ranged from 76 to 83% for seed protein and from 68 to 86% for the sum of protein and oil, while narrow sense heritability ranged from 34 to 72% for seed protein and from 39 to 65% for the sum of protein and oil. Narrow sense heritability values equalled broad sense values for seed oil and ranged from 58 to 68%. Heritability was also estimated from standard unit parent – progeny regression analyses and values for all three traits were found to approach the variance analyses estimated broad sense heritabilities. Comparisons with the results of late maturing soybean crosses are made and implications of the results obtained in this study on early maturing soybean breeding programs are discussed.Key words: Glycine max, heritability, 00 and 000 maturity groups, breeding strategies.


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