scholarly journals Selection of parents for low nitrogen stress through the combining ability of maize partially inbred lines

2019 ◽  
Vol 41 ◽  
pp. e42705
Author(s):  
Rafael Heinz ◽  
Larissa Pereira Ribeiro ◽  
Manoel Carlos Gonçalves ◽  
Leonardo Lopes Bhering ◽  
Paulo Eduardo Teodoro

The objective of this work was to estimate the general combining ability of partially inbred lines under high and low nitrogen (N) conditions and to select promising lines to obtain high yields for both conditions. Fifty-five partially inbred S1 progenies were evaluated using the top-cross method, where the lines were crossed with two testers. The 110 top-cross hybrids were evaluated for grain yield during the off-season of 2012 at two sites in the Brazilian Midwest. Partial diallel analysis was performed with the adjusted means of each of the individual analyses of the top crosses. The combining ability of partially inbred lines and testers as well as their interaction with N levels, was estimated for each site. The coefficient of concordance among 15 partially inbred lines selected by the highest general combining ability estimates for each N level was 0.60. The S1 lines 39, 11, 41, 55, 38, 37, 6, 8, and 14 were selected at both N levels. This indicates that these lines can be used to identify ideal hybrids for growing in the off-season in the Brazilian Midwest.

2018 ◽  
Vol 10 (3) ◽  
pp. 253
Author(s):  
Casper Nyaradzai Kamutando ◽  
Cosmos Magorokosho ◽  
Shorai Dari

The International Centre for Maize and Wheat Improvement (CIMMYT) develops maize (Zea mays L.) inbred lines and hybrids yearly that have several breeding and commercial attributes. However, no genetic analysis has been done on the recently developed inbred lines for yield performance under drought and low-N stress. The objectives of this study were to identify lines with positive general combining ability (GCA) effects for grain yield under stress environments and to identify the best single-cross hybrids with the highest specific combining ability (SCA) effects. Analysis of variance combined across sites showed significant mean squares for genotypes, locations and genotype by environment interaction (GEI) for grain yield. GCAlines, SCA and components of interaction effects were significant across sites. Additive genetic variance was more important than dominance variance in determining yield performance across locations indicating that selection based on grain yield under drought and low-N stress can be effective. Average grain yield across the eight locations ranged from 1.61 t ha-1 to 10.63 t ha-1 while narrow sense heritability for grain yield was 52.6% across sites and was slightly lower under managed drought and low-N stress. The testers CL115807 and CL106622 showed positive and significant GCA effects for yield performance under drought and low-N stress respectively. The best tester across all sites was CL115793 and line CZL0713 had consistently positive GCA effects for grain yield across sites. CML536 × CL115802 and CML312 × CL106508 were the best single crosses under low nitrogen stress sites while hybrid CML312 × C323-45 showed the highest positive SCA effects across sites. In conclusion, our results show that CIMMYT has new lines that have desirable adaptive attributes when grown under drought and low nitrogen stress environments in the mid-altitude region; hence these can be adopted for hybrid, synthetic and OPV formation.


2021 ◽  
Vol 20 (04) ◽  
pp. 1-9
Author(s):  
Hiet D. Hoang

The study on General Combining ability (GCA) of 15 cucumber inbred lines (I5) was carried out at the Research and Development Center for High-tech Agriculture, Ho Chi Minh City. The objective of the study was to identify the appropriate parental lines for producing F1 hybrid cucumber cultivars. Experimental materials included 15 cucumber inbred lines (I5) (L3, L9, L21, L22, L28, L32, L33, L36, L39, L61, L63, L69, L71, L74 and L78) and two test lines (T1 - TN 456 from Trang Nong Company, imported from Thailand and T2 - Cuct 1450 from Chia Tai - Thailand), forming 30 hybrid combinations by the method of topcross. The results showed that seven inbred lines including L3, L9, L21, L28, L33, L61 and L71 had high ability to combine with both T1 and T2 tester lines abby fruit yield with GCA index from + (0.8) to + (9.4). Evaluation of 30 cucumber hybrid was combinations on the growth and fruit yield characteristics showed that L28/T1 and L71/T2 hybrids were significantly different from other hybrids with high yields of 43.1 tons/ha and 41.3 tons/ha, respectively


Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 699-703 ◽  
Author(s):  
A. E. Dorrance ◽  
K. H. Hinkelmann ◽  
H. L. Warren

A diallel cross of seven inbreds and one synthetic line of maize were analyzed in 1994 and 1995 for their reaction to Diplodia ear rot. An additional inbred line was included in the 1995 analysis. Plants were inoculated by placing a pycnidiospore suspension (5 × 103 spores per ml) of Stenocarpella maydis in the whorl at the V14 to V15 growth stage. Crosses were evaluated for disease incidence of Diplodia ear rot at harvest, and the percentage of plants with Diplodia ear rot in a plot was used for analysis. In both years, general combining ability (GCA) effects were significant. In 1995, specific combining ability effects were also significant. There were no reciprocal effects. There was no significant interaction between year and genotypes, indicating that crosses reacted the same in both years. Inbred lines B37, H111, B68, and MS had negative GCA effects that contributed toward resistance in both years. VA26, with intermediate resistance to Diplodia ear rot, contributed toward susceptibility. Only inbred lines with a high degree of resistance should be used as parents.


1972 ◽  
Vol 52 (4) ◽  
pp. 545-550
Author(s):  
P. J. LOESCH Jr. ◽  
M. S. ZUBER

We evaluated 66 inter se crosses among 12 inbred lines of maize in 2 years at two locations. The inheritance of ash content of the stalk was determined by means of diallel analysis. Significant differences in ash content among the 66 F1 hybrids were obtained. General combining ability (GCA) and specific combining ability (SCA) mean squares were also statistically significant. The additive genetic variation was much larger than the nonadditive variation. Interactions of GCA and SCA with locations and with years × locations were significant. The broad sense heritability estimate for ash content of stalk was.62. The primary objective, to determine whether ash content of the stalk is positively associated with susceptibility to stalk lodging, was only partially supported. The genotypic correlation between ash content of stalk lodging was relatively low (+.280) and of little predictive value.


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.


Author(s):  
S. D. Nehru ◽  
Akshata Timmanna Budihal ◽  
M. S. Umar Farooq ◽  
Y. G. Shadakshari ◽  
M. S. Uma ◽  
...  

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.


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 ◽  
...  

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.


2015 ◽  
Vol 39 (4) ◽  
pp. 675-683
Author(s):  
MN Amin ◽  
M Amiruzzaman ◽  
A Ahmed ◽  
MR Ali

Maize inbred lines were evaluated by using line × tester method involving 11 lines and 3 testers for grain yield and its components through estimation of general combining ability (gca) and specific combining ability (sca) effects. Highly significant genotypic differences were observed indicated wide range of variability present among the genotypes. The crosses with high sca effect for grain yield were evolved from high × low general combiner parents which reveled additive × dominance type of gene action. The cross combinations 9MS4-1 × L22, 9MS4-1 × L486, 9MS4-2 × L431, 9MS4-11 × L486 and 9MS4- 15 × L431 with high positive sca effect having high mean values might be used for obtaining high yielding hybrids. The information on the nature of gene action with respective variety and characters might be used depending on the breeding objectives. DOI: http://dx.doi.org/10.3329/bjar.v39i4.22547 Bangladesh J. Agril. Res. 39(4): 675-683, December 2014


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