scholarly journals Combining Ability Analysis of Juvenile Period in Pear

HortScience ◽  
1990 ◽  
Vol 25 (11) ◽  
pp. 1425-1427 ◽  
Author(s):  
Richard L. Bell ◽  
Richard H. Zimmerman

Combining ability for transmission of juvenile period duration was studied in a large pear breeding population. The 92 parents, consisting of cultivars and selections of Pyrus communis L. and its interspecific hybrids with P. pyrifolia (Burm.) Nakai and P. ussuriensis Maxim., as well as genotypes of P. calleryana Decne., were crossed in 298 combinations. General combining ability was highly significant and of much larger magnitude than specific combining ability, indicating that juvenile period length was under predominantly additive genetic control. Selection of parents based on their juvenile period or their combining ability constants is likely to result in significant reduction in mean juvenile period.

2019 ◽  
Vol 48 (2) ◽  
pp. 231-237
Author(s):  
Tao Yang ◽  
Yawen Zeng ◽  
Juan Du ◽  
Shuming Yang ◽  
Xiaoying Pu

Genetic analysis of 4 major flavonoids in barley interspecific hybrids which were used as parents for half diallel crossingwas carried out. Compared with seven parents, the highest general combining ability of catechin content was Clipper barley, the higest general combining ability (GCA) of myricetin content were Schooner barley and Huangchangguang barley, the highest general combining ability of quercetin content were Ziguangmang barley and Kuanying barley, the highest general combining ability of kaempferol content were Ziguangmang barley and Schooner barley, the highest general combining ability of flavonoids are Schooner barley and Huangchangguang barley. The hybrid combination of a good matching were Clipper barley, Schooner barley, Ziguangmang barley and Kuanying barley, as a comprehensive general combining ability, specific combining ability, and combinations of which can be used as flavonoids in barley breeding.


Author(s):  
A. D. Takyun ◽  
M. S. Mohammed ◽  
A. Usman

Late leaf spot (LLS) Phaeoisariopsis personata (Berk. and Curtis) Deighton is one of the most important foliar diseases of groundnut worldwide including Nigeria. The genotypes were used to estimate the general combining ability (GCA) and specific combining ability (SCA) for yield components and late leaf spot (LLS) resistance. Four susceptible genotypes (SAMNUT 23, SAMNUT 24, SAMNUT 25 and SAMNUT 26) were used as females and five resistant genotypes (ICGV 12991, ICGV 7878, FDR-F7 82, FDR-F7 67 and FDR-F7 61) were used as males using line x tester mating design with three replications. The parents and progenies were evaluated for late leaf spot resistance. Highly significant negative general combing ability (GCA) effects were recorded for disease incidence in SAMNUT 25 (-0.05), indicating the genotype is a good general combiner for late leaf spot (LLS) and SAMNUT 26 (-5.90) is a good general combiner for LLS disease severity. ICGV 12991 (-12.00), FDR-F7 67 (-.68) and FDR-F7 61 (-2.23) genotypes are good general combiner for late leaf spot (LLS) disease resistance (disease incidence and severity), among the crosses, significant and negative SCA effects were obtained for most of the crosses i.e SAMNUT 24 x FDR-F7 67 and SAMNUT 24 x FDR-F7 61 for late leaf spot (LLS) resistance indicating that they are good specific combiners for late leaf spot (LLS) resistance. The ratio of the general combining ability (GCA) and specific combing ability (SCA) variances indicated the preponderance of specific combining ability (SCA) variance over general combining ability (GCA) variance for disease incidence and severity, indicating the role of non-additive gene effect and it may be due to difference in genotypes used as parents.


Author(s):  
Anamika Nath ◽  
S. R. Maloo ◽  
Baudh Bharti ◽  
R. B. Dubey ◽  
Rajani Verma

A diallel method was employed in which eight genotypically diverse lines of mungbean were crossed among themselves in all possible combinations excluding reciprocals. The mean square due to general combining ability (GCA) and specific combining ability (SCA) were significant for all the characters except mean square due to (SCA) for clusters per plant and seed yield per plant indicating importance of both additive as well as non-additive gene action. The estimates of variances due to specific combining ability were higher than general combining ability for all the traits except days to 50 % flowering, primary branches per plant, clusters per plant and seed yield per plant pointed out to be the preponderance of non-additive gene effects in the expression of these characters. Whereas predictability ratios were greater than the value of 0.5 for days to 50 % flowering, primary branches per plant, clusters per plant and seed yield per plant indicating the predominance of additive gene action for these characters. However, predictability ratio exhibited less than 0.5 values for rest of the characters indicating the predominance of non- additive gene action. The good general combiners for seed yield per plant were BM-4, PDM-139, ML-131, and IPM 99-125. The best specific cross combinations wereRMG-344 x RMG-1045, RMG-1035 x RMG-1045 and BM-4 x PDM-139. showed the highest positive significant SCA effect for seed yield per plant. These cross combinations could be utilized for further use in breeding programme for improvement in yield of mungbean.


1966 ◽  
Vol 46 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Eric D. Putt

Heterosis occurred for the eight plant and seed characters studied. It was most frequent for yield of seed and height of plant. Mean squares for general combining ability (gca) and specific combining ability (sca) were significant (P =.01) for all characters. The estimated components for gca were greater than for sca for days to mature, weight per bushel, and percent oil in the seed; less for height and yield of seed; and essentially the same for days to bloom, diameter of head, and weight per 1000 seeds.The yield of seed and percent oil in the seed, for the highest ranking 100 synthetics that could be composed from the 10 lines, was predicted in F6 assuming 50 and 60% outcrossing between F2 and F6. Virtually all values exceeded the mean performance of four check samples of commercial hybrids. Many exceeded the highest rank check for oil content in the seed. Fourteen of the highest ranking 100 synthetics for yield and 30 for oil content consisted of two or three lines. It was concluded that synthetics can be superior to the present hybrids in heterosis and that desirable synthetics can be made from only a few lines.


1969 ◽  
Vol 11 (4) ◽  
pp. 810-822 ◽  
Author(s):  
D. R. Knott ◽  
S. S. Sindagi

Diallel crosses were made among six varieties of hard red spring wheat that differed considerably in yield and other characteristics. The F1 hybrids were tested at two seeding rates and the F2, hybrids at one. Heterosis was not great in either generation and no cross appeared to be promising. General combining ability was much more important than specific combining ability and parental yields gave reasonable predictions of hybrid yields. Yields of hybrids at the two seeding rates were closely correlated.


1999 ◽  
Vol 22 (3) ◽  
pp. 451-456 ◽  
Author(s):  
Cleso Antônio Patto Pacheco ◽  
Cosme Damião Cruz ◽  
Manoel Xavier dos Santos

The objective of the present work was to provide a methodology to study the inheritance of adaptability and stability through the breakdown of Eberhart and Russell regression coefficients and regression deviations in effects due to the mean and additive genetic effects (gi's and gj's) as well as dominance effects (sij's) of Griffing´s methodology, when the diallel is conducted in several environments. It was concluded that the adaptability and stability parameters are determined in the same manner as are genetic effects. So an F1 cross inherits half the general combining ability (GCA) mean effect from each parent, while the effects due to specific combining ability (SCA) are subjected to the same considerations relative to sij's, i.e., they are dependent on specific combinations.


2009 ◽  
Vol 66 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Leonardo Oliveira Medici ◽  
Salete Aparecida Gaziola ◽  
Vanderlei Aparecido Varisi ◽  
José Antonio Carmezini de Paula ◽  
Renato Rodrigues Ferreira ◽  
...  

Six S5 lines of maize, with differences for lysine and oil contents in grains, were used to carry out a complete series of diallelic crosses. The resulting 15 hybrids were grown in a field at two nitrogen levels (10 and 130 kg N ha-1). The general combining ability (GCA) and specific combining ability (SCA) were obtained by using the method 4, model I of Griffing for grain yield, and grain lysine and oil contents. Significant (p < 0.001) interaction was observed between GCA and N levels for grain yield, indicating the selection of different lines for each N level. This interaction was not significant for lysine content, but there were significant effects of GCA for this trait at both N levels (p < 0.1). Significant effects were not observed for GCA or SCA for oil content, however a positive correlation was observed between lysine and oil contents in the hybrids, in the lines and even in the control cultivars. The results indicate the effectiveness of selection for lysine content, irrespective of N level, in the studied non-opaque maize lines, and the possibility of achieving both high lysine and oil content in grains.


Author(s):  
В. В. Ващенко ◽  
О. О. Шевченко

У системі діалельних схрещувань п’яти сортів яч-меню ярого (Донецький 12, Донецький 14, Донецький 15,Прерія, Галактик) установлено особливості генети-чного контролю мінливості ознак: висота рослин,кількість зерен у колосі, маса 1000 зерен у відповід-ності зі співвідношенням варіанс специфічної комбі-наційної здатності (СКЗ) і загальної комбінаційноїздатності (ЗКЗ). Виділено й запропоновано сорти якджерела ознак висота рослин Галактик і Донецький14; кількість зерен у колосі – сорт Прерія; маса 1000зерен – сорт Донецький 15. Виділені зразки з високимі стабільним рівнем комбінаційної здатності запро-поновано використовувати в селекційній роботі. A total of diallel analysis varieties of springbarley Donetskiy 12, Donetskiy 14, Donetskiy 15,Prairie, Galactic set features genetic controlvariability characteristics: plant height, number ofgrains per ear, 1000 grain weight in accordance withthe ratio of variance of specific combining ability(SSI) and general combining ability (ZKZ).Identified and proposed as a source of variety traitsplant height and Donetsk 14, Galactic, the numberof grains per ear sort Prairie, weight of 1000 grainsDonetskiy 15. Samples of high and stable levels ofcombining ability is proposed to use in breedingwork have beeen celected.


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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