Thrips (Thysanoptera: Thripidae) Tolerance in Cotton: Sources and Heritability

1997 ◽  
Vol 32 (4) ◽  
pp. 460-471 ◽  
Author(s):  
Daryl T. Bowman ◽  
Jack C. McCarty
Keyword(s):  
North Carolina ◽  
Gossypium Hirsutum ◽  
Combining Ability ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
General Combining Ability ◽  
Sources Of Resistance ◽  
Gossypium Hirsutum L ◽  
F2 Generation ◽  
F1 Generation

Thrips (Thysanoptera: Thripidae) resistance or tolerance in cotton, Gossypium hirsutum L., is often associated with extreme pubescence. This is undesirable because hairy (pubescent) plants tend to have more trash in harvested lint which reduces the price received by growers. Two other possible sources of resistance include gossypol and thick lower epidermal cells, the latter has been found in G. barbadense L. Five G. barbadense genotypes were mated in a North Carolina Design II to 4 upland cultivars to evaluate combining ability. In addition, 90 converted racestocks were screened for tolerance to thrips. Experiments were designed to evaluate tolerance or resistance by comparing plots with and without thrips. Two G. barbadense parents had tolerance to thrips while two upland cultivars also exhibited tolerance. In the F1 generation, general combining ability was significant for thrips damage ratings among the G. barbadense parents. In the F2 generation, all characters exhibited specific combining ability. Thus, non-additive genetic variance predominates measures of thrips tolerance.

GENETIC NATURE OF TWO INDEXES OF COMPATIBILITY IN ALFALFA

1971 ◽  
Vol 13 (1) ◽  
pp. 51-54 ◽  
Author(s):  
S. M. Singh ◽  
K. Lesins
Keyword(s):  
Combining Ability ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Relative Magnitude ◽  
General Combining Ability ◽  
Total Variance ◽  
Reciprocal Effects ◽  
Diallel Crosses ◽  
Yielding Ability ◽  
Number Of Seeds

Seven clones selected for their high seed and forage yielding ability were crossed in a diallel manner to obtain the estimates of GCA, SCA and reciprocal effects of the parental clones in various hybrid combinations. The analysis of the diallel crosses revealed that the variances for GCA, SCA and reciprocal effects were significant (0.01 level) for percentage of pod set during the crossing program. Number of seeds per pod set were significant for the general combining ability. The general combining ability appeared to be of greater importance for both the characters studied, and the additive genetic variance seems to constitute approximately 63% of the total variance for percentage of pod set and 71% of the total variance for number of seeds per pod set. However, wide differences were found among the clones in the relative magnitude of GCA, SCA and reciprocal effects for both traits.

scholarly journals Estimating Combining Ability Effect of the Indian and Exotic Lines of Tomatoes by Partial Diallel Analysis

2015 ◽  
Vol 3 (9) ◽  
pp. 715
Author(s):  
Suresh Baban Dagade ◽  
Nanadasana Jagdish Nasibhai ◽  
Hariprasanna Krishna ◽  
Bhatt Virendra Mulshankar ◽  
Dhaduk Lallubhai Keshavbhai ◽  
...  
Keyword(s):  
Combining Ability ◽  
Additive Genetic Variance ◽  
Diallel Analysis ◽  
Fruit Weight ◽  
General Combining Ability ◽  
Fruit Firmness ◽  
Equatorial Diameter ◽  
Additive Gene ◽  
F2 Generation ◽  
Pericarp Thickness

Eight nearly homozygous, horticulturally superior and optimally divergent lines of tomato having Indian and exotic adaptability were used for carrying out half diallel design to study General Combining Ability (GCA) and Specific Combining Ability (SCA) estimates for fruit weight, polar and equatorial diameter, locules fruit-1, pericarp thickness and fruit firmness. The variances due to both GCA and SCA were significant, suggesting that both additive and non additive genetic variance were involved for genetic control of the character fruit polar and equatorial diameter, and locules number in F1 and F2 generations. However, the variance due to GCA was more pronounced for fruit weight, pericarp thickness and firmness as a result of additive gene action. Due to their high general combining ability effects, exotic parents Ec 490130 and Ec 177371 producing firm fruited small to medium sized tomato fruits having constant expression of GCA effects over the generationsregarded as best general combiners. The crosses GT 1 x Ec 490130 and Ec 490130 x Ec 398704 having high x high and high x low combinations, respectively in F1. While in F2, GT 1 x Ec 177371 and H 24 x Ec 490130 having high x high and high x low combining lines were considered as best crosses for greater fruit firmness. Therefore, heterosis breeding in F1 and selection of desirable lines in F2 generation is recommended for further improvements were suggested for future hybridization programmes.

scholarly journals Combining ability for yield and yield attributes in rice (Oryza sativa l.) genotypes using CMS system

2014 ◽  
Vol 11 (1) ◽  
pp. 23-33 ◽  
Author(s):  
CL Sharma ◽  
NK Singh ◽  
AK Mall ◽  
K Kumar ◽  
ON Singh
Keyword(s):  
Combining Ability ◽  
Genetic Variance ◽  
Gene Action ◽  
Oryza Sativa L ◽  
Additive Genetic Variance ◽  
Hybrid Breeding ◽  
Male Sterile ◽  
Yield Attributes ◽  
Genetic Components ◽  
Per Se

Seventy five hybrids generated from crossing three cytoplasmic male sterile lines with 25 testers were studied along with parents for combining ability and gene action involved in expression of characters in rice. The GCA and SCA effects were significant for all the characters except seedling height, indicating the importance of both additive and non additive genetic components. The ratio of gca and sca variance was less than unity for all the characters also indicated preponderance of non additive genetic variance and suggested good prospects of the exploitation of variation through hybrid breeding. Amongst the parental lines, UPR-2080-24-1-R, IR-60076-1-R, PNR-165-10-6-R and IR-58025- A were found to be good general combiners which can be taken up to generate desirable segregates for further selection. None of the crosses showed significant sca effects for all the characters. On the basis of per se performance and high sca effects, IR-58025-A x CSRC-50-2-1-4-BR, PMS-10-A x IR-42688-2-118-6-3, RPMS-100-A x UPRI-92-79-R and NMS-4-A x IR-32419-28-3-1-3-R were good specific combiners for grain yield plant-1 and their components which could be used for exploitation of heterosis for yield. DOI: http://dx.doi.org/10.3329/sja.v11i1.18372 SAARC J. Agri., 11(1): 23-33 (2013)

scholarly journals Performance of testers with different genetic structure for evaluation of maize inbred lines

2012 ◽  
Vol 42 (5) ◽  
pp. 770-776 ◽  
Author(s):  
Lauro José Moreira Guimarães ◽  
Glauco Vieira Miranda ◽  
Rodrigo Oliveira DeLima ◽  
Ciro Maia ◽  
Lucimar Rodrigues de Oliveira ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Combining Ability ◽  
Genetic Variance ◽  
Inbred Lines ◽  
General Combining Ability ◽  
Specific Combining Ability ◽  
Genetic Base ◽  
Maize Inbred Lines ◽  
Single Cross ◽  
Single Cross Hybrids

The objective of this study was to evaluate four maize testers for identification of superior inbreed lines in testcross. The four testers evaluated are cultivars with narrow or wide genetic base (single-cross hybrids and open pollinated varieties) and two kernel types (flint or dent). SynD and SynF testers are open pollinated varieties with dent and flint kernels, respectively, and FSH and DSH testers are single-cross hybrids with flint and dent kernels, respectively. SynD tester showed the biggest genetic variance among the maize inbreed lines in crosses. The effects of general combining ability (GCA) for lines and specific combining ability (SCA) for lines x testers were significant, whereas GCA effects for testers were not significant. SynD and SynF testers identified the largest number of lines with higher GCA. The DSH and FSH testers showed suitable to identify lines with high SCA. It was concluded that SynD and SynF testers are adequate to identify inbreed lines with high GCA effects, and it's possible to identify new lines with high heterotic potential in each one of the four testers.

COMBINING ABILITY FOR YIELD OF SYNTHETIC HEXAPLOID WHEATS

1974 ◽  
Vol 54 (2) ◽  
pp. 235-239 ◽  
Author(s):  
R. J. BAKER ◽  
P. L. DYCK
Keyword(s):  
Triticum Aestivum ◽  
Seed Yield ◽  
Combining Ability ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Triticum Aestivum L ◽  
Kernel Weight ◽  
Specific Combining Ability ◽  
Synthetic Hexaploid Wheats ◽  
Synthetic Hexaploid

Four hexaploid spring wheats (Triticum aestivum L.), which differ only in their D genomes, were crossed in all combinations. Heterosis was expressed in F1 and F2 for number of spikes, kernel weight, and seed yield. Failure to detect significant specific combining ability among F1 progeny suggests that only additive genetic variance is involved in the inheritance of these traits. Competition between single-spaced plants was detected.

scholarly journals Estimates of heterosis and combining ability of soybean diallel crossings

Plant Omics ◽  
2020 ◽  
pp. 7-14
Author(s):  
Jose Ricardo Bagateli ◽  
Carlos André Bahry ◽  
Raimunda Nonata Oliveira da Silva ◽  
Ivan Ricardo Carvalho ◽  
Giordano Gelain Conte ◽  
...  
Keyword(s):  
Combining Ability ◽  
General Combining Ability ◽  
Specific Combining Ability ◽  
Plant Yield ◽  
Plant Seeds ◽  
Heterosis Effect ◽  
Number Of Seeds ◽  
F1 Generation ◽  
Partial Diallel

This study aimed to estimate the general and specific combining ability of partial soybean diallel crossings. The parents were divided in two groups contrasting for the characteristics of mass of thousand seeds, maturity group, flowers’ color, lodging and growth aspect. The scheme of partial diallel followed the Griffing model, where it were included the parents and the F1 generation. There was predominance of additive genic effects for the characteristics number of seeds per pods, number of seeds per plant and plants height. For number of pods per plant, seeds per plant and mass of hundred seeds the dominance effects were expressed by the superiority of specific combining ability in the determination of these characters. The parents G3 and G7 were the ones that contributed the most to the increase in yield in function of general combining ability for the characters number of pods per plant, seeds per plant, plant yield and mass of hundred seeds. The hybrids from the crossings between G3 x G5 and G3 x G4 are more promising for the characteristics related to yield, since they present elevated heterosis effect and high specific combining ability associated to increase general combining ability presented by the parent G3.

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