scholarly journals Comportamiento de híbridos de maíz y aptitud combinatoria de líneas con caracteres contrastantes.

2016 ◽  
Vol 9 (2) ◽  
pp. 97
Author(s):  
Narciso Vergara ◽  
Shivaji Pandey ◽  
Surinder Kumar ◽  
Scott D. McLean ◽  
Sergio Rodríguez

Twelve long-eared and twelve thick-eared lines were identified for this purpose. Single crosses were evaluated using a 12 x 12 simple lattice design with four replications in five environments during 1995. General combining ability (GCA) and Specific combining ability (SCA) estimates for grain yield were ca1culated using line x tester analysis. Line 4 (Pop.21xPop.43) registered the highest GCA value (0,58 t/ha) among long-eared lines; while in the group of thick-eared lines the highest GCA values (0,48 t/ha) corresponded to line 19 (Pop.25). The highest yield (8,35 t/ha) and SCA effect of (0,61 t/ha) was produced by cross 4 x 22 (Pop.21xPop.43) x (Pop.32). Results showed that it is important to consider the use of lines with different traits and their heterotic pattern to develop hybrids maximizing Fl performance.

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


2017 ◽  
Vol 9 (1) ◽  
pp. 60-67
Author(s):  
Navin Chander Gahtyari ◽  
P. I. Patel ◽  
Rakesh Choudhary ◽  
Sudhir Kumar ◽  
Naveen Kumar ◽  
...  

Line x tester analysis using a set of four females, ten males and their forty hybrids was carried out to esti-mate the general combining ability of parents and specific combining ability of hybrids for yield and ten other associ-ated components in rice (Oryza sativa L.) in a Randomized Block Design during Kharif 2011. GCA variances for females (s2f) were significant at 0.1% level of significance for plant height (40.8), no. of grains per panicle (505.9), grain yield per plant (29.1), test weight(17.9), straw yield per plant (61.3) and kernel L/B ratio (0.2) whereas specific combining ability (SCA) variances for f x m interactions were highly significant for all the characters. Non-additive gene action was prevalent in all characters (Range: 0.03 in amylose content to 0.88 in kernel length breadth ratio) except plant height (1.33) as evident by low GCA to SCA ratio. None of the parents were good general combiner for all traits, however, female IR-28 and male AMT-119 and PNR-546 were good general combiners for a maximum number of traits i.e. five traits out of eleven.. The general combining ability for grain yield per plant for female parent Gurjari (6.19) and NVSR-178 (5.29); and male parents AMT 119 (2.73) and PNR 546 (2.44) makes them a good choice for improving yields in a hybridization programme as these female and male parents are also having signifi-cant GCA effects for maximum number of yield associated traits i.e. four and five traits out of eleven for female and male parents respectively. A vis-à-vis comparison of top three specific combining ability crosses with their mean performance showed correlation and these crosses were having at least one good general combining ability parent.


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


Author(s):  
Abdullah Khan ◽  
◽  
Hidayat Ur-Rahman ◽  
Ashfaq Ahmad ◽  
Muhammad Iqbal ◽  
...  

Aim The purpose of this study was to investigate the different combination of testcrosses for morphological and yield relating traits and to investigate general combining ability of the inbred lines. Materials and Methods This research was conducted at The University of Agriculture Peshawar, Pakistan during 2016. Line x-tester analysis was used to test general combining ability (GCA) effects of 24 S4 lines of sweet corn. Alpha lattice design with two replications and two checks was used during the experiment. Research data were recorded on various flowering, morphological and yield parameters. Results Highly significant variations were recorded among the testcrosses for the studied traits except anthesis silking interval (ASI), 100-kernel weight. Minimum days to tasseling (48-days) and silking (53.5-days) was exhibited by pop-syn-swt (9-4)×synthetic sweet. GCA effect was -2.14 for tasseling and -2.00 for silking. Maximum value (3.5-days) for ASI was recorded for Pop-synswt 1(8-3)×synthetic sweet, while GCA effect for ASI was -0.71. Lowest plant height (129.8 cm) was recorded for pop-syn-swt 1(3-3)×synthetic sweet, while GCA effect for plant height was observed to be -14.79. Maximum cob length (16.6 cm) was revealed by pop-syn-swt 1(12-2)×synthetic sweet. For cob length GCA effect of 1.01 was recorded. Maximum 100 kernel weight (31.3 g) was estimated for pop-syn-swt 1(2-1)×synthetic sweet. GCA effect of 1.85 was recorded for 100-kernel weight. Highest mean (7143.9 kg ha-1) for grain yield was recorded for pop-syn-swt 1(9-4)×synthetic sweet. GCA effect for grain yield was found to be 1370.93. Conclusion Generally a low GCA value, either positive or negative indicates that the mean of a parent does not largely vary from its offsprings. In contrast, high GCA value suggests that parent is either superior or inferior to the general mean and it has high heritability and less environmental effects. Based on the findings in this research, the above mentioned testcrosses can be included in future sweet corn breeding programs where early flowering and yield attributes is desired.


Author(s):  
Nageshwar . ◽  
Bijendra Kumar ◽  
Hariom Suman ◽  
A. H. Madakemohekar ◽  
Dattesh Tamatam

This experiment was conducted to determine the general and specific combining abilities and heterosis for grain yield and yield associated traits in pea as a source of protein through line x tester analysis. Grain yield and its inheritance were carried out for investigation through a 12 x 3 line x tester analysis. Experimental materials comprising 15 parents and their 36 hybrids. The materials were planted in a randomized block design with three replications. The general combining ability and Specific combining ability effects were significant indicating the presence of both additive and non-additive types of gene actions. Heterosis was determined as the superiority over mid parent heterosis as well as better parent (HBP). Grain yield showed highly significant heterosis ranging from -36.29 to 8.77and relative heterosis ranged from -25.85 to 13.19 respectively.


1976 ◽  
Vol 86 (3) ◽  
pp. 537-542 ◽  
Author(s):  
H. G. Nasr ◽  
W. Khayrallah

SummaryThe F1 and F2 generations of a diallel cross of six-row barley involving the parents, Beecher, Athenais, Atlas 46, 3130-4564-3, and 3130-864-4 were studied and heterosis, inbreeding depression, and combining abilities were measured for grain yield, number of tillers per plant, number of kernels per plant, kernel weight, and plant height. Significant heterosis was detected for grain yield in two of the ten crosses, for number of tillers per plant in one cross, for number of kernels per plant in two crosses, for plant height in three crosses, and for kernel weight in none of the crosses. The inbreeding depression of the F2 generation was present in most cases but significantly so in a few. Atlas 46 x 3130-4564-3 exhibited inbreeding depression for grain yield, number of kernels per plant, and plant height.The general combining ability (GCA) mean squares of both generations were significant for all characters studied except number of kernels per plant in the F1 generation. The specific combining ability (SCA) mean squares were significant for only plant height in the F1 generation and all characters studied except number of tillers per plant in the F2 generation.The GCA effects indicated that Beecher and Athenais are good general combiners for grain yield and its components. The latter parent produced good yielding hybrids with slightly shorter plants than the remaining hybrids.The SCA effects revealed that Athenais × 3130-4564-3, Athenais × 3130-864-4, and Beecher × Atlas 46 seem good specific combinations for high grain yield. Also, the former two crosses tend to produce shorter plants.


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.


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