Alfalfa resistance to post-harvest Aspergillus species: Combining ability analyses

2004 ◽  
Vol 84 (4) ◽  
pp. 1193-1197
Author(s):  
C. A. Kimbeng ◽  
S. R. Smith Jr. ◽  
V. Babij ◽  
K. M. Wittenberg

Hay making is still the most widespread technique of forage preservation. Saprophytic fungi, such as Aspergillus repens, can reduce forage quality during the post-harvest period by causing hay molding. Methods to control molding have yielded variable results, but genetic resistance has yet to be exploited. The objective of this study was to determine the mode of inheritance of resistance to post-harvest fungal growth in alfalfa. Seven parental genotypes representing a range of resistance to fungal growth (A. repens) were crossed in a complete diallel including reciprocals for a total of 42 crosses. Parental genotypes along with their progeny were screened for resistance to A. repens. The relative importance of general combining ability (GCA) and specific combining ability (SCA) effects in controlling resistance to post-harvest A. repens was compared. The results revealed a preponderance of GCA effects. The parent that supported the least amount of fungal growth produced progeny with the least amount of fungal coverage. The reverse was true for the more susceptible parents. The results indicate that breeding procedures that maximize additive gene effects, such as recurrent selection, could be effective in improving resistance to post-harvest fungal growth in alfalfa. Key words: Alfalfa, breeding, combining ability, resistance, Aspergillis repens, post-harvest fungi

Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Aiswarya C. S. ◽  
Vijeth S ◽  
Sreelathakumary I ◽  
Prashant Kaushik

Chilli pepper is commercially cultivated as a spice and is also used for the extraction of a colouring agent. Here, we performed a diallel genetic study involving five chilli pepper varieties. Parents and their hybrid were evaluated for fifteen morphological and five biochemical traits over two crop seasons under open field conditions. Variation was recorded for all of the studied traits. Similarly, significant values for general combining ability (GCA) and specific combining ability (SCA) variance were obtained for all of the traits. The ratio of σ2 SCA/σ2 GCA indicates that non-additive gene effects were predominant for all the studied traits except for fruits plant−1. Based on SCA effects, cross combinations P2 × P5, and P4 × P5 were determined excellent for flesh thickness, yield components and vitamin C. These hybrids are recommended for multilocation testing to assess their suitability for commercial cultivation. Overall, this work presents useful information regarding the genetics of important morphological and biochemical traits in chilli pepper.


2018 ◽  
Vol 43 (4) ◽  
pp. 599-609
Author(s):  
ANMS Karim ◽  
S Ahmed ◽  
AH Akhi ◽  
MZA Talukder ◽  
A Karim

Combining ability effects were estimated for grain yield and some other important agronomic traits of maize in a 7×7 diallel analysis excluding reciprocals. The variances for general combining ability (GCA) were found significant for yield, days to pollen shedding, days to silking and ear height while it was found non-significant for plant height and number of kernels/ear. Non-significant general combining ability (GCA) variance for plant height and number of kernels/ear indicates that these two traits were predominantly controlled by non- additive type of gene action. Specific combining ability (SCA) was significant for all the characters except yield and days to silking. Non-significant specific combining ability (SCA) variance for yield and days to silking suggests that these two traits were predominantly controlled by additive type of gene action. Both GCA and SCA variances were found significant only in days to pollen shedding and ear height indicated the presence of additive as well as non additive gene effects for controlling the traits. However, relative magnitude of these variances indicated that additive gene effects were more prominent for all the characters studied except days to silking. Parent BIL95 was the best general combiner for both high yield and number of kernels/ear and parent BML4 for dwarf plant type. Two crosses (BML4× BML36 and BIL114× BIL31) exhibited significant and positive SCA effects for grain yield involved low × average and average × average general combining parents. The range of heterosis expressed by different crosses for grain yield and days to silking was from -65.83 to 21.26 percent and -17.85 to 8.22 percent, respectively.. The better performing three crosses (BIL114×BIL31, BIL138×BIL95 and BIL31×BIL95) can be utilized for developing high yielding hybrid varieties as well as for exploiting hybrid vigour.Bangladesh J. Agril. Res. 43(4): 599-609, December 2018


2010 ◽  
Vol 62 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Yuksel Bolek ◽  
Hatice Cokkizgin ◽  
Adem Bardak

Combining ability and heterosis for fiber quality traits in cotton Combining ability analysis and heterosis for cotton fiber quality traits were studied in a set of diallel crosses involving eight cotton (Gossypium sp.) genotypes. Randomized complete block design was used to test 56 F1 and 8 parents for fiber quality traits; length (Len), strength (Str), micronaire (Mic), uniformity (Unf), elongation (Elg), spinning consistency index (Sci) and short fiber index (Sfi). Analysis revealed significant general combining ability (GCA) and specific combining ability (SCA) effects for all the traits and additive gene effects were important in the inheritance of the traits. Giza-45 had the highest GCA effects for Len, Sci, Unf and Elg while Is-4 had the highest Str value. Mic and Sfi values were lowest for Askabat-100 and Giza-45, respectively. The cross Cukurova-1518 × 108-F and Nazilli-84S × Askabat-100 had the lowest SCA effects for Mic and Sfi, respectively. The highest values for Len (Askabat-100 × 108-F), for Str (Acala Prema × 108-F), for Sci (Is-4 × Giza-45), for Unf (Stoneville-453 × Askabat-100) and for Elg (108-F × Is-4) were also obtained. Hybridizations among Askabat-100 × Nazilli-84S, Is-4 × Giza-45, Askabat-100 × Stoneville-453, Askabat-100 × Giza-45, Is-4 × 108F, Giza-45 × 108F, Giza-45 × Acala Prema, Nazilli-84S × Giza-45, Is-4 × Nazilli-84S and Acala Prema × Askabat-100 crosses yielded the best heterosis and heterobeltiosis values. Aforementioned parents and crosses could be utilized for further selection of high fiber quality and applying 3-way crosses or modified backcross or recurrent selection to genotypes having good combining ability would improve fiber quality.


HortScience ◽  
2001 ◽  
Vol 36 (7) ◽  
pp. 1315-1317 ◽  
Author(s):  
Yayeh Zewdie ◽  
Paul W. Bosland ◽  
Robert Steiner

The inheritance of capsaicinoid content was studied in five Capsicum pubescens Ruiz & Pav. genotypes using diallel analysis. General combining ability and specific combining ability effects were significant for all capsaicinoids studied, indicating additive and nonadditive gene actions are present. The association of high capsaicinoid contents with high positive general combining ability of the parents also indicates the predominance of additive gene action in capsaicinoid inheritance. Because of the predominant additive gene effect, recurrent selection would be a good breeding method to increase capsaicinoid level in the population studied. Heterosis was observed in hybrids for some of the capsaicinoids, suggesting that F1 hybrids could also be used to increase capsaicinoid content.


2021 ◽  
Author(s):  
Onur Karaağaç

Abstract Interspecific hybrid Cucurbita rootstocks (Cucurbita maxima × Cucurbita moschata) are the most widely used rootstocks for Cucurbitaceous vegetables in the world. In recent years, scientists have focused on understanding and exploiting root architectures as new opportunities for crop improvement. Selection of parents and hybrids based on combining ability test is an effective approach in interspecific hybrid variety breeding. However, very little information is available on the combining ability tests for the rooting and graft-related traits in these rootstocks. Ondokuz Mayis University and Black Sea Agricultural Research Institute are conducting a program to breed Cucurbita rootstocks of Turkey for fifteen years. In this study, seven C. maxima (BC5F1 generation) lines as female parents and three C. moschata (S6 generation) lines as male parents were used to obtain 21 crosses. Interspecific hybrids and their parent rootstocks grafted onto watermelon were analyzed in terms of general combining ability (GCA), specific combining ability (SCA), heritability, and heterosis for roots and graft-related traits including root volume (cm3), root length (m), root dry weight (g), hairy root rate (%), average root diameter (mm), shoot dry weight (g), graft success rate (%), and hypocotyl thickness ratio (%) by using line × tester mating design. The quotient of GCA/SCA effects for all root and hypocotyl traits were higher than 1, suggesting the preponderance of additive over non-additive gene action in the expression of these traits, whereas graft success was controlled by additive and non-additive gene effects. It was determined that average root diameter had high heritability (63.85%) and the other traits had intermediate heritability ranging from 40.59% to 58.98%. Combining ability analyses indicated that FTS5, GH12, and GRD17 lines were promising parents with greater general combining ability. Three crosses, GRD17 × FTS5, B12 × FTS5, and BH5 × CHI2 showed superior mid-parent heterosis and significant SCA for most characters. Present findings will provide significant contributions in understanding of inheritance and then achieving desirable improved rootstocks in C. maxima × C. moschata.


2020 ◽  
pp. 5-14
Author(s):  
Maamoun A. Abdel-Moneam ◽  
M. S. Sultan ◽  
Waleed A. E. Abido ◽  
Ágnes Hadházy ◽  
S. A. Sadek ◽  
...  

Combining ability estimation is an important genetic attribute for maize breeders in anticipating improvement in productivity via hybridization and selection. This research was carried out to investigate the genetic structure of the 27 F1 maize hybrids established from nine lines derived from Maize Research Department and three testers, to determine general combining ability (GCA), determine crosses showing specific combining ability (SCA) and superiority percentages for crosses. Nine lines, three testers, 27 F1 hybrids and two check commercial hybrids (SC162 and SC168) were studied in randomized complete block Design (RCBD) with three replications during 2016. The results of mean squares showed that significant and highly significant for most studied traits (days to 50% tasseling, days to 50% silking, plant and ear height, ear position, ear length, no. of kernels per row, 100-kernel weight and Grain yield). Estimates of variance due to GCA and SCA and their ratio revealed predominantly non-additive gene effects for all studied traits. Lines with the best GCA effects were: P2 (line 11) and P6 (line 21) for grain yield, for testers Gm174 and Gm1021 had significant GCA effects for grain yield. The hybrids P5×Gm1021, P6×Gm1021, P7×Gm1021, P8×Gm1002, P9×Gm1002 had significant and negative SCA effects for grain yield. Crosses P1×Gm174, P2×Gm1002, P5×Gm1021, P6×Gm174, P6×Gm1021, P7×Gm1021, P8×Gm1002, P9×Gm1021 were the best combinations manifested and significant superiority percentages over than check varieties (SC162 and SC168) for most studied traits. Therefore, these hybrids may be preferred for hybrid crop development. Abbreviations: GCA general combining ability; SCA specific combining ability


2016 ◽  
Vol 50 (6) ◽  
Author(s):  
G. B. Vaidya ◽  
D. A. Chauhan ◽  
B. H. Kale ◽  
A. B. Patil

Seven genotypically diverse lines of mungbean were crossed in diallele fashion to identify genotypes with high general combining ability and specific cross combinations with high specific combining ability for yield and yield attributes in rabi season excluding reciprocals. The analysis for combining ability revealed significant mean sum of squares due to general and specific combining ability for all the characters studied indicating importance of both additive as well as non-additive gene effects involved in the expression of all the characters. Higher magnitude of general combining ability variances for most of the traits except for number of branches per plant, pod length, number of seeds per pod and harvest index pointed out the preponderance of additive component of the genetic variance in the expression of the characters under study. The good general combiners for yield attributing traits were Co-4, GBM-1 and Meha and the best specific cross combinations having the highest SCA effect for yield and yield attributing traits were Co-4 x Meha, Co-4 x GBM-1, Rm-9-126 x Rm-9- 134, GBM-1 x Meha and Rm-9-133 x GBM-1. This cross combinations could be utilized for further breeding programmes for the development of rabi mungbean varieties with chilling tolerant ability or photo-thermo insensitivity, so as to exploit potential of rabi mungbean in rice fallows of heavy rainfall zone.


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.


2006 ◽  
Vol 144 (1) ◽  
pp. 63-68 ◽  
Author(s):  
VICTOR O. ADETIMIRIN ◽  
SOON-KWON KIM ◽  
M. SZCZECH

Seventeen supersweet Shrunken-2 (sh-2) maize lines and progenies of their crosses to two sh-2 hybrid testers were investigated for factors responsible for differences in field emergence in Korea in studies carried out in the field, greenhouse and laboratory. The lines and their testcrosses showed significant genetic variation for emergence. Two lines showed significant positive general combining ability (GCA) for emergence while two other lines had significant negative GCA effects. Because none of the specific combining ability effects was significant, emergence was primarily influenced by additive gene action, and could, therefore, be improved by recurrent selection. Seed weight was significantly (P<0·05) correlated with emergence for inbreds (r=0·63) and testcross progeny involving the tester with the lower mean seed weight (r=0·54). Two lines also showed significant positive GCA effects for seed weight. The lines with positive GCA effects for emergence were different from those with positive GCA for seed weight, indicating that factors other than seed weight influence field emergence. The severity of Fusarium infection of seeds of the lines was significantly correlated to germination (r=−0·61, P<0·05) and emergence (r=−0·67, P<0·01), suggesting that practices that prevent pathogenic field infection, such as timely harvest and treatment with fungicides, are crucial for high seed quality. The field emergence of sh-2 inbred parents did not give an indication of emergence in hybrid combinations.


2011 ◽  
Vol 41 (6) ◽  
pp. 967-971 ◽  
Author(s):  
Rafael Egea Sanches ◽  
Carlos Alberto Scapim ◽  
Dauri José Tessmann ◽  
Rafael Augusto Vieira ◽  
Marcos de Araújo Rodovalho ◽  
...  

The objectives of this study were to identify promising popcorn lines and hybrids for genetic resistance to tropical rust (Tr, Physopella zeae) in diallel crosses of nine lines derived from a large part of Brazilian popcorn germplasm and to estimate genetic parameters for Tr resistance. Crosses and checks were tested in a random block design, with artificial inoculations under greenhouse conditions. Plots consisted of a single 14-L pot, with four plants. Tr was measured by severity and area under the disease progress curve. Data was analyzed by Griffing's diallel model, and genetic parameters were estimated. Heritability estimates to Tr resistance was medium. Specific combining ability-SCA had significant effects (P<0.10) for resistance, and was eight to nine times larger than general combining ability-GCA (P>0.10). This indicated the major importance of non additive gene effects. In general, breeding possibilities for resistance was restricted. The line 9 (L7.4) had the most outstanding GCA for resistance to Tr, and hybrids 1×7 and 3×6 had outstanding SCA and were recommended for breeding.


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