Genetics of Graft Rejection in Douglas-fir

1974 ◽  
Vol 4 (2) ◽  
pp. 186-192 ◽  
Author(s):  
Donald L. Copes
Keyword(s):  
Graft Rejection ◽  
Combining Ability ◽  
Tree Improvement ◽  
Douglas Fir ◽  
Breeding Program ◽  
Specific Combining Ability ◽  
Graft Incompatibility ◽  
Additive Genes

Graft rejection in Douglas-fir was controlled primarily by additive genes. Heritability of graft incompatibility was 0.81. No significance for specific combining ability was found. A breeding program to develop highly compatible stocks should enable tree improvement workers to substantially reduce incompatibility losses within clonal orchards. Highly incompatible clones may have different or additional rejection factors which less incompatible clones do not exhibit.

scholarly journals Inheritance of plant height, spike length and number of spikelets per spike in Durum wheat

2007 ◽  
pp. 27-33 ◽  
Author(s):  
Biljana Gorjanovic ◽  
Marija Kraljevic-Balalic
Keyword(s):  
Durum Wheat ◽  
Plant Height ◽  
Combining Ability ◽  
Wheat Breeding ◽  
Specific Combining Ability ◽  
Spike Length ◽  
First Year ◽  
Gene Effects ◽  
Breeding Programs ◽  
Additive Genes

Using the line x tester analysis we studied the combining ability and gene effects of plant height, spike length and number of spikelets per spike in durum wheat. The results of the study show that non-additive genes play more important role than additive genes in the inheritance of plant height, number of spikelets per spike in both years and in inheritance of spike length only in the first year of research. Variety Belfugito, the best general combiner for plant height and number of spikelets per spike, combined well in two best hybrids: Belfugito x Alifen and Belfugito x Yavaros 79, and these hybrids may be used in wheat breeding programs. In the majority of the cases, good specific combining ability (SCA) effects were associated with crosses of two genetically divergent parents having at least one parent as a good general combiner.

scholarly journals Daya Gabung dan Heterobeltiosis Karakter Pertumbuhan dan Hasil Beberapa Galur Backcross Cabai Merah Toleran CMV pada Kondisi Terinokulasi

2018 ◽  
Vol 45 (3) ◽  
pp. 292
Author(s):  
Catur Herison ◽  
Rustikawati , ◽  
Dan Merakati Handajaningsih
Keyword(s):  
Capsicum Annuum ◽  
Combining Ability ◽  
Vegetative Growth ◽  
Fruit Weight ◽  
General Combining Ability ◽  
Breeding Program ◽  
Specific Combining Ability ◽  
Selected Lines ◽  
Combining Abilities ◽  
Hybrid Variety

<p align="center"><strong><em>ABSTRACT<br /><br /></em></strong><em>Information on combining ability and heterosis are desirable to determine the best parents in chili pepper hybrid variety development. To estimate general and specific combining abilities and  heterobeltiosis of backcross lines selected for CMV tolerance, eight selected lines were crossed to three CMV tolerant lines in a Line x Tester method and the crosses were evaluated in a CMV inoculated condition. The results showed that general and specific combining abilities varied tremendously among crosses and traits. Generally, specific combining ability (sca) variances were higher than general combining ability (gca) variance indicating that interaction of non-aditive predominance the inheritance of traits under study. Amongs lines evaluated, there was no a general combiner line for vegetative growth. However, lines S1B3A-29-13-47 and S1B3B-12-13-2 were the best general combiner for a breeding program to improve total number of fruits and fruit weight per plant, respectively. Crosses of S1B3C-16-22-34 x C1042, S1B3B-49-40-6 x C1043, and S1B3C-34-18-9 x C1042 were consedered the most prospective crosses as indicated by high value of sca, i.e., 130.53, 102.01 and 61.93, with heterobeltiosis estimate of 146.06, 26.05 and 24.31, respectively.</em><em><br /><br />Keywords: capsicum annuum, heterobeltiosis, GCA, SCA <br /></em><em><br /></em><strong><em><br /></em></strong></p><em></em><em></em>

scholarly journals Efficient Method of Choosing Potential Parents and Hybrids: Line  Tester Analysis of Spring Wheat (Triticum aestivum L.) Cultivars

2011 ◽  
Vol 54 (3) ◽  
pp. 117-121
Author(s):  
Muhammad Jurial Baloch ◽  
Inayat Ali Mallano ◽  
Abdul Wahid Baloch ◽  
Wajid Ali Jatoi ◽  
Nasreen Fatima Veesar
Keyword(s):  
Plant Height ◽  
Combining Ability ◽  
Triticum Aestivum L ◽  
Specific Combining Ability ◽  
Spike Length ◽  
F1 Hybrids ◽  
Ability Estimates ◽  
Crop Development ◽  
Seed Index ◽  
Additive Genes

The study was conducted to estimate the general combining ability (GCA) and specific combining ability (SCA) of wheat genotypes crossed in a line ´ tester fashion. The mean squares due to F1 hybrids, female lines, male testers/pollinators and lines ´ tester interaction were significant for majority of the characters studied. The significance of GCA and SCA variances thus suggested that both additive and non- additive genes were controlling majority of the characters, yet additive genes were more prominent because variances due to GCA by and large were higher than due to SCA. Among the three female lines evaluated, Khirman displayed maximum positive GCA effects for spike length (0.08) and seeds/spike (0.67), while other female lines which showed maximum positive GCA effects were Mehran for plant height (3.05), number of tillers/plant (1.00), spikelets/spike (1.92) and seed index (3.42) and Kiran for seeds/spike (0.67) and yield/plant (1.86). From the male testers, TD-1 exhibited greater GCA effects for number of tillers/plant (2.96), spikelets/spike (0.25), seed index (0.61) and yield/plant (2.22), whereas, Marvi displayed highest positive GCA effects for plant height (2.88), spike length (0.37) and seeds/spike (6.41). The specific combining ability estimates indicated, if hybrid crop development is feasible then, crosses Mehran ´ TD-1 for spike length; Kiran ´ TD-1 for plant height and seeds/spike and Khirman ´ Marvi for number of tillers/plant, spikelets/spike, seed index and yield/plant may be the hybrids of choice.

scholarly journals General and Specific Combining Ability Estimates for Morphological, Yield and its Attributes and Seed Traits in Sunflower (Helianthus annuus L.)

2018 ◽  
Vol 61 (3) ◽  
pp. 126-135
Author(s):  
Muhammad Jurial Baloch ◽  
Muhammad Siddique Depar ◽  
Qumar-Uddin Chacher
Keyword(s):  
Combining Ability ◽  
Specific Combining Ability ◽  
F1 Hybrids ◽  
Male Sterile ◽  
Negative Effects ◽  
Crop Development ◽  
Dominant Genes ◽  
Additive Genes ◽  
Selection Of

The improvement in sunflower breeding requires exploitation of combining ability of divergent male and female inbreds. Six cytoplasmic male sterile (CMS) lines and three testers were crossed in line ´ tester  design, thus 18 F1 hybrids were developed for evaluation of  general combining ability (GCA) and specific combining ability (SCA) of inbred parents for days to 90% maturity, stem girth, head size, achenes/plant, 1000-seed weight, achene yield kg/ha, oil and  protein%. The significant variances due to lines and testers both determined GCA variances revealed the predominance of additive genes whilst significance of lines ´ tester interactions indicated the importance of SCA variances and the involvement of non-additive genes in the expression of traits studied. The foremost role of non-additive genes was apparent when ratio s2 SCA/s2GCA was above 1.0. These results suggested the prevalence of dominant genes and possibility of hybrid crop development. The GCA effects indicated that CMS parents SF-187, 64-A-93 and ARG-0405 and tester RHP-46 were high general combiners, thus may be chosen for crossing  and  selection programmes, whereas F1 hybrids SF-187 ´ RHP-46, 64-A-93 ´ RHP-46, PAC-ARG-0405   PAC-ARG-0106, 64-A-93 ´ RHP-46 and PSF-025 ´ RHP-64 which used parents with good ´ good and good ´ poor GCA estimates revealed higher positive SCA estimates for achene yield, oil and protein traits yet manifested desirable negative effects for 90% maturity. Such results suggested that these hybrids are desirable for the exploitation of hybrid crop development or selection of desirable plants from earlier filial generations.

scholarly journals Differential Tolerances to Ametryne Among Six Genotypes of Giant Bermudagrass [Cynodon dactylon (L.) Pers. var. Aridus Harlan et de Wet], and Their Diallel Progenies

1969 ◽  
Vol 61 (1) ◽  
pp. 49-56
Author(s):  
G. Ramírez-Oliveras
Keyword(s):  
Combining Ability ◽  
Cynodon Dactylon ◽  
General Combining Ability ◽  
Specific Combining Ability ◽  
Breeding Programs ◽  
Heritable Trait ◽  
Additive Genes

Six parental giant bermudagrass [Cynodon dactylon (L.) Pers. var. Aridus Harlan et de Wet] clones and their F1 progenies from 27 crosses out of a possible 30, were evaluated for their responses to two concentrations [5 and 10 p/m weight per volume (w/v)] of Ametryne [2-(ethylamino)- 4(esopropylamino)-6-(methylthio)-s-triazine]. There were significant differences among parents and progenies at 10 but not at 5 p/m Ametryne. Tolerant parents had more tolerant progenies than did susceptible parents, indicating that tolerance may be a heritable trait. Progenies had tolerance ratings consistently lower than midparent values, suggesting that susceptibility is partially dominant. General combining ability, but not specific combining ability, was significant for the 10 p/m test, suggesting that breeding programs for tolerance to Ametryne should proceed in terms of additive genes. Crosses of tolerant parents should be expected to produce a high proportion of tolerant progeny.

scholarly journals Heterosis, habilidad combinatoria y diversidad genética en híbridos comerciales de maíz (Zea mays L).

2006 ◽  
Vol 11 (1) ◽  
pp. 113
Author(s):  
Alfredo De la Rosa ◽  
Humberto De León ◽  
Gaspar Martínez ◽  
Froylan Rincón
Keyword(s):  
Genetic Diversity ◽  
Zea Mays ◽  
Genetic Distance ◽  
Combining Ability ◽  
Zea Mays L ◽  
Genetic Distances ◽  
Breeding Program ◽  
Specific Combining Ability ◽  
Maize Breeding ◽  
Genetic Value

Knowledge about the combining ability, genetic diversity and heterosis of germoplasm from a maize breeding program is essential for hybrids and varieties development. The objetives of this study were (1) To identify commercial hybrids with high genetic value (GCA and heterosis) useful for initiating a maize breeding program to produce and improved hybrids, varieties and synthetics; (2) To demonstrate that is feasible to create a maize breeding program from commercial hybrids. Estimates of general (GCA) and specific combining ability (SCA) were obtained using the method IV of Griffing (1956) and the genetic distances were estimated according to the method suggested by Troyer (1988). The best crosses were AS910 X AS4450 and PP9538 X AS948 having a yield of 17.538 and 17.463 t/ha respectively; the same crosses had the highest values of SCA. The crosses with the highest values of heterosis over the midparent were PP9539 X AN453 and PP9603 X PP9539 with 11,35 and 11,13 percent respectively. The highest positive values of GCA effects were obtained from hybrids PP9539 and AN447 with 1.168 and 0.684 t/ha respectively;. and the hybrids with the best heterosis were PP9539 ( 2.269 ) and A7500 ( 1.170 ). The most related hybrids were AS910 and AN450 with a genetic distance of 0,033 and heterosis of -47,68 percent whereas the most diverse were AN454 and A7500 with a genetic distance of 1.418 and heterosis of 12,26 %.

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