Determining genetic combining ability, heterotic potential and gene action for yield contributing traits and Yellow Vein Mosaic Virus (YVMV) resistance in Okra [Abelmoschus esculentus (L.) Monech.]

2020 ◽  
pp. 1-14
Author(s):  
Anjan Das ◽  
Ramesh Kumar Yadav ◽  
Harshawardhan Choudhary ◽  
Saurabh Singh ◽  
Yogesh P. Khade ◽  
...  

Abstract Breeding for resistance to biotic stress and higher yield is a continuous process. Thus, the identification of desirable parents with good combining ability and nature of gene action for the target trait is of utmost importance. Hence, in this present investigation, 10 lines and three testers of Okra were crossed in line × tester mating design to generate 30 testcross progenies and their evaluation along with parents and check in a randomized complete block design with three replications. To depict the true picture of genetic variation among the parental genotypes, molecular diversity analysis was also carried out using genomic-simple sequence repeats before crossing to ascertain that sufficient variability is present among the parents. The molecular analysis grouped the parental genotypes into four clusters (I–IV). The analysis of variance revealed that all the treatments were significant for most of the traits. The combining ability analysis suggested Pusa A-4 as the best general combiner for earliness, Pusa Bhindi-5 for high yield, and DOV-92 for fruit length, plant height, yield per plant, and coefficient of infection for Yellow Vein Mosaic Virus Disease resistance. Similarly, the specific combining ability analysis suggested that the cross combinations DOV-92 × Pusa Bhindi-5 followed by DOV-92 × Pusa A-4 and DOV-92 × Pusa Sawani exhibit high economic heterosis for yield per plant as well as for disease resistance. Finally, estimation of the degree of dominance and predictability ratio was also worked out which indicated the prevalence of non-additive gene action for most of the traits pointing towards sufficient scope for heterosis breeding in Okra.

2019 ◽  
Vol 17 (04) ◽  
pp. 346-351
Author(s):  
SamanthiKumari Wasala ◽  
Sumudu I. Senevirathne ◽  
Jayantha Bandara Senanayake ◽  
Anuradini Navoditha

AbstractWild relative of okra, Abelmoschus angulosus Wall. ex Wight & Arn. was identified as a resistant germplasm for Okra Yellow Vein Mosaic Virus (OYVMV) which is the devastating disease for okra cultivation in Sri Lanka. The mode of resistance of OYVMV in A. angulosus was studied with the aim of tagging responsible genes for the disease resistance. Wide hybridization was performed between A. angulosus and highly virus susceptible A. esculentus variety, MI-7. Very poor seed setting was observed in F1 and F2 generations due to post zygotic abortion. Disease screening was carried out using F1 and F2:3 populations along with parents in the field under induced disease pressure. Disease severity index and area under disease progress curve were calculated to measure disease severity. Number of genes segregating for OYVMV disease resistance was calculated for the F2:3 generation. Modified Wright's formula was used to estimate the effective gene number and mode of inheritance by a quantitative method. A χ2 test was performed for qualitative analysis. Plants of A. angulosus were totally free of virus incidence while 100% disease incidence was observed in the variety MI-7. F2:3 population showed between and within progeny segregation for disease incidence. Results indicated that the disease susceptibility was dominant over resistance. χ2 analysis revealed that the segregation of disease severity was significantly fit to the gene model of 9:6:1 (χ2 = 0.1757 at P ≤ 0.05) suggesting the disease resistance in A. angulosus is governing by two recessive genes in an additive manner. Result was confirmed by the quantitative analysis.


Author(s):  
Dharma Oraon ◽  
Anjani Kumar ◽  
Ranjay Kumar Singh ◽  
U. K. Singh ◽  
Zunaid Alam

An On-Farm Trial (OFT) was conducted in the year 2016-17 and 2017-18 to assess the resistance level of different okra varieties against yellow vein mosaic virus in Kharif season of Chatra district of Jharkhand. The experiment was conducted in vegetable growing village Gidhour in Gidhour block of Chatra district in Jharkhand. The trial was designed in randomized block design consisting of 20 replications with three technological option i.e. TO-I Arka Abhay (N100P60K50), TO-II Arka Anamika (N100P60K50) and-III Pusa Makhmali (N100P60K50). For assessment related to yellow vein mosaic, percentage infestation in 5sqm and yield q/ha and economic was considered. The lowest infestation of yellow vein mosaic virus was observed in Pusa Makhmali variety i.e. (3.8%) with yield of 132.5 q/ha. It was also found superior in terms of Gross Income, Net Income and Benefit: Cost Ratio followed by Arka Anamika and Arka Abhay, respectively. Farmers’ response was also positive in all respects except the availability of varieties in local market.


Author(s):  
A. Munir ◽  
S. Ali ◽  
M. A. Zeshan ◽  
M. U. Ghani ◽  
A. A. Khan

Okra (Abelmoschus esculentus L.) is susceptible to number of diseases like Yellow Vein Mosaic Virus disease, Damping Off, Fusarium wilt, Powdery Mildew and Enation Leaf Curl. The Okra is favorite host of whitefly which transmits the okra Yellow Vein Mosaic Virus (OYVMV). OYVMV disease causes considerable yield losses in Okra. Experiment was conducted to check the efficacy of organic matter (poultry manure, leaves) and insecticides (Acetamiprid, Diafenthiuron, Pyridine Carboxamide) against OYVMV and its whitefly vector. In this experiment, ten okra varieties were sown in randomized complete block design (RCBD). Organic matter and insecticides were applied at recommended doses (@5ml/L) on weekly intervals. Among insecticides, Acetamiprid showed the best result to manage whitefly infestation with 60.01% mortality and OYVMV disease severity with 53.98% efficiency. Polo (Diafenthiuron) also showed good results to manage whitefly (56.36%) and OYVMVD (46.34%), but Ulala (Pyridine Carboxamide) insecticide was least effective to control whitefly population (47.27%) and to manage the infection of OYVMV disease (43.91%). Leaf manure was more effective with 61.16% efficiency as compared to poultry manure (56.01%) against OYVMV disease severity. New chemistry insecticide (acetamiprid) gave the most effective control of whitefly and transmission of OYVMV and could be used in place of conventional insecticides. Leaf manure proved significant defense activator in okra plants with effective control of disease and could be used as eco-friendly management approach.


1970 ◽  
Vol 23 (2) ◽  
pp. 1-6
Author(s):  
R Podder ◽  
MG Rasul ◽  
AKMA Islam ◽  
Mak Mian ◽  
JU Ahmed

A half diallel set of five parents and their 10 F1’s were studied to determine the combining ability and magnitude of heterosis for eight important characters in snakegourd at the experimental field of Bangabandhu Sheikh Mujibur Rahman Agricultural University during April to July, 2004. Combining ability analysis revealed that both general and specific combining ability variances were significant for all the characters except fruit diameter and fruit yield per plant. Predominance of additive gene action was noted for all the characters except days to first female flower where non-additive gene action was predominant. Parent P1 was the best general combiner for fruit yield and some yield contributing characters. Among the crosses P2  X P3, P1  X P2 and P1  X P4 were the best specific combiner for fruit yield and some of yield contributing characters. Both positive and negative heterosis was obtained of which few hybrids showed desirable and significant values. P2  X P5 showed the highest significant mid parental heterotic value for earliness and high yield whereas, P1  X P2, P2  X P3, P2  X P5 and P3  X P4 showed the highest significant better parent heterotic effect for earliness and high yield. Key words: Snakegourd (Trichosanthes cucurminata L.); combining ability; heterosis; fruit yieldDOI: http://dx.doi.org/10.3329/bjpbg.v23i2.9318 Bangladesh J. Pl. Breed. Genet., 23(2): 1-6, 2010


2019 ◽  
Vol 7 (2) ◽  
pp. 63-74
Author(s):  
Sieh S. Kargbo ◽  
Francis Showemimo ◽  
Pius Akintokun ◽  
Justina Porbeni

Salinity is a major abiotic constrain faced by farmers in most rice cultivating areas of the world and improving grain yield in rice is the most important breeding objective. Twenty seven hybrids were generated in a line x tester mating design and were evaluated with their parents in a Randomized Complete Block Design at the Fadama site of the Federal University of Agriculture, Abeokuta (FUNAAB) during the 2014/2015 and 2015/2016 cropping season. Analysis of variance revealed a highly significant difference (P0.01) among testers and lines for all traits except panicle length and a number of effective tillers per plant, respectively. Variances of Specific Combining Ability (SCA) were higher in magnitude than the corresponding General Combining Ability (GCA). The lines FARO 60 (P7), OG300315 (P10), NERICA L53 (P4) including a tester ITA 212 (P1) were the best general combiners for yield per plant. POKKALI (P3) was the best general combiner for reduced vegetative growth and ITA 212 (P1) and ITA 222 (P2) were the best general combiners for plant height. The best specific combiner for yield per plant was P1 x P4. P3 x P11 was the best specific combiner for reduced duration characters and P2 x P7 was the best specific combiner for plant height.  Estimates of narrow sense heritability (0.00 – 0.03) for all the traits under study were low which indicated preponderance of non-additive gene action governing these traits. Therefore, inter-mating among selected segregants followed by recombination breeding in an advanced generation might be advocated for improvement of the studied traits under salinity.


Genetika ◽  
2017 ◽  
Vol 49 (3) ◽  
pp. 1001-1014 ◽  
Author(s):  
Hasanalideh Haghighi ◽  
Ezatollah Farshadfar ◽  
Mehrzad Allahgholipour

In order to study the combining ability, genetic parameters and gene actions of yield, yield components and quality characters in rice, fifteen F2 generation of a 6?6 diallel cross, excluding reciprocals, was grown in a randomized complete block design (RCBD) with three replications. The results of analysis of variance showed significant differences between the genotypes for grain yield (GY), 100-grain weight (HGW), number of panicles per plant (PN), panicle length (PL), number of full grains per panicle (FGN) and for quality characters including amylose content (AC) and gel consistency (GC). The results of combining ability analysis revealed that general combining ability (GCA) and specific combining ability (SCA) were significant for characters GY, FGN, GC, AC, HGW and PN indicating the involvement of additive and non-additive effects in their inheritance, however high amounts of Bakers ratio remarked that additive gene effect had more portion in controlling these traits. The best combiners for GY, HGW, FGN, PN and PL, were RI18447-2, IR 50, Daylamani, RI18430-46 and Daylamani respectively. For AC and GC, the best combiner was Daylamani. Hayman's graphs showed that regression line passed below the origin cutting Wr axis in the negative region for HGW, PN, PL and GC, indicating the presence of over dominance. Estimates of genetic parameters showed significant amount of H1 and H2, and non-significant amount of D for the characters GY, PN, PL and GC, which confirmed the existence of dominance in the inheritance of these traits.


Author(s):  
B. C. Nandeshwar ◽  
Beka Biri ◽  
Alemayehu Dugassa

Combining ability analysis provides information about the gene action involved in the expression of a trait and facilitates breeding of superior cultivars. Hence, 45 hybrids evolved from 10 parent half-diallel were evaluated for combining ability to identify good general combiners and superior cross combinations for high ethanol yield from sweet sorghum. RSSV-21-2 has been identified as the best general combiner. It can be used in pedigree breeding programme for the incorporation of desired traits for enhancing ethanol yield. ARS-SS-35-1 × NSS-218 and ARS-SS-83 × NSS-221-2 have been identified as the best specific combinations. These could be exploited in heterosis breeding programme.


1990 ◽  
Vol 115 (3) ◽  
pp. 509-512 ◽  
Author(s):  
Geok Yong Tan

Six Trinitario females of cacao (Theobroma cacao L.) were crossed with nine Amazonian males in a factorial crossing design. The 54 hybrid progenies were used to estimate genetic variability due to general combining ability (GCA) and specific combining ability (SCA) for yield, pod production, pod weight, husk content, number of beans per pod, average bean weight, and pod value. The results demonstrated that GCA differed significantly for all characteristics from all three sources (Le., female + male, female, and male). SCA (female × male) was also significantly different for all characteristics. The ratio of GCA to SCA ranged from 7.1 for number of beans per pod to 25.7 for pod weight. This result suggested that a major portion of the genetic variability was additive in nature for these characteristics. Among the six Trinitarios, KA2-106 was the best female parent; it contributed high yield and all the desirable pod and bean characteristics into the hybrid progenies. Trinitario KA2-101 combined high pod production and yield, but tended to transmit below-average pod and bean characteristics to its progenies. Amazonians KEE6 and KEE12 were the two highest-yielding male parents, but had below-average bean number per pod and average bean weight. KEE42 and KEE43 combined high yield and transmitted good pod and bean characteristics to their progenies. Based on the GCA effects and the mean performance of the hybrid progenies, a multi-line cultivar consisting of 20 high-yielding crosses with good pod and bean characteristics is being produced in seed gardens for commercial planting.


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