Evaluation of Maize Populations as Sources of Favorable Alleles for Improvement of Two Single‐Cross Hybrids

Crop Science ◽  
1995 ◽  
Vol 35 (5) ◽  
pp. 1353-1359 ◽  
Author(s):  
Duška Stojšin ◽  
L. W. Kannenberg
2009 ◽  
Vol 57 (3) ◽  
pp. 255-265
Author(s):  
G. Evgenidis ◽  
V. Mellidis ◽  
C. Karamaligkas ◽  
M. Koutsika-Sotiriou

This study aimed to assess the response of eight maize populations and their 28 diallel crosses to water stress and conventional irrigation. The source populations consisted of maize germplasm from CIMMYT and the F 2 generation of commercial single-cross hybrids. The trials were conducted at three locations in two successive years. Six characteristics relevant to drought stress were recorded. On average, water stress reduced the plant height and ear attachment height, and increased the number of days to silking and the anthesis to silking interval (ASI). The reductions were greater in the diallel crosses, and the increases in the parental populations. At one location, where irrigated and drought-stressed treatments were established side by side, diallel analysis for yield revealed that: (i) the control (B73 × Mo17) and the commercial hybrid Costanza had significantly reduced yield under drought stress; (ii) the general (GCA) and specific (SCA) combining ability were significantly higher in the irrigated experiments; and (iii) populations derived from the F 2 generation showed higher GCA.


2017 ◽  
Vol 16 (1) ◽  
pp. 120
Author(s):  
BELISA CRISTINA SAITO ◽  
JOÃO ANTÔNIO DA COSTA ANDRADE

RESUMO - O objetivo do trabalho foi a identificar linhagens com alta capacidade de combinação visando o desenvolvimento de híbridos simples adaptados à condição de elevada densidade populacional de plantas. Treze linhagens originadas de duas populações de milho braquítico foram cruzadas seguindo o esquema de dialelo parcial (6x7). Os híbridos simples foram avaliados em duas safras (primeira e segunda safras). Os efeitos da interação entre as capacidades gerais de combinação (CGC) e safras foram diferentes para rendimento de grãos apenas para linhagens Isanão-VD1, enquanto que para a altura de plantas, altura de espigas e acamamento mais quebramento os efeitos da interação CGCs x safras foram diferentes para ambos os grupos de linhagens. Levando em consideração apenas o rendimento de grãos, os melhores híbridos são esperados entre as linhagens IVF1-5 e IVF1-10 da população Isanão VF1 e IVD1-1 e IVD1-2 da população Isanão-VD1. Considerando-se todos os caracteres, as linhagens promissoras para a primeira safra são IVF1-6, IVD1-1 e IVD1-5, e para a segunda safra as linhagens são IVF1-10, IVD1-8 e IVD1-9. Os híbridos mais adequados são IVF1-10 x IVD1-5 para primeira safra e IVF1-10 x IVD1-8 e IVF1-10 xIVD1-9 para a segunda.Palavras-chave: dialelo parcial, capacidade geral de combinação, capacidade específica de combinação.POTENTIAL OF INBRED LINES DERIVED FROM BRACHYTIC MAIZE POPULATIONS FOR OBTAINING HYBRIDSABSTRACT - The objective of this study was to identify parents with high combining ability aiming at the development of outstanding hybrids. Thirteen inbred lines originated of two brachytic maize populations were crossed following the partial diallel (6x7) scheme. The single-cross hybrids were evaluated in two crop seasons (regular crop and second crop). The effects of interaction general combining abilities (GCAs) x seasons were different for yield only for lines of Isanão-VD-1, while for plant height, ear height and stalk lodging and breaking, the effects of interaction GCAs x seasons were different for both groups of lines. Taking into account only the grain yield, the best hybrids are expected between the inbred lines IVF1-5, and IVF1-10, of the population Isanão-VF1 and IVD1-1 and IVD1-2 and IVD1-5 of the population Isanão-VD1. Considering all the traits, the inbred lines promising for the first crop are IVF1-6, IVD1-1 and IVD1-5 and for the second crop are the inbred lines IVF1-10, IVD1-8 and IVD1-9. The most suitable hybrids are IVF1-10 x IVD1-5 for the first crop and IVF1-10 x IVD1-8, and IVF1-10 xIVD1-9 for second crop.Keywords: partial diallel, general combining ability, specific combining ability.


Euphytica ◽  
2021 ◽  
Vol 217 (8) ◽  
Author(s):  
Oula Maafi ◽  
Pedro Revilla ◽  
Lorena Álvarez-Iglesias ◽  
Rosa Ana Malvar ◽  
Abderahmane Djemel

AbstractDrought is the main stress for agriculture, and maize (Zea mays L.) germplasm from the Sahara has been identified as potential source of drought tolerance; however, information about adaptation of semitropical maize germplasm from the Sahara to temperate areas has not been reported. Our objective was assessing the adaptation of maize germplasm from Saharan oases as sources of drought tolerance for improving yield and biomass production under drought conditions in temperate environments. A collection of maize populations from Saharan oases was evaluated under drought and control conditions in Spain and Algeria. Algerian populations were significantly different under drought for most traits, and the significant genotype × environment interactions indicated that drought tolerance is genotype-dependent, but tolerance differences among genotypes change across environments. Based on yield, the Algerian maize populations PI527474, PI527478, PI527472, PI527467, PI527470, and PI527473 would be appropriate sources of drought tolerance for temperate environments. Concerning biomass production, the most interesting populations were PI527467, PI542685, PI527478, and PI527472. These Saharan populations could provide favorable alleles for drought tolerance for temperate breeding programs, and could also be used for studying mechanisms and genetic regulation of drought tolerance.


2021 ◽  
Vol 13 (2) ◽  
pp. 78
Author(s):  
L. Musundire ◽  
J. Derera ◽  
S. Dari ◽  
A. Lagat ◽  
P. Tongoona

Grain yield potential of new maize hybrid varieties across target environments contributes to the uptake of these varieties by farmers. Evaluation of single-cross hybrids developed from test crossing introgressed inbred lines bred for three distinct environments to elite tropical inbred line testers was carried out. The study’s objective was to assess grain yield stability and genotype adaptability of the single-cross hybrids across South African environments relative to adapted commercial hybrid checks. One hundred and twenty-two introgressed inbred lines developed using the pedigree breeding program were crossed to four tropical elite inbred line testers using line × tester mating design to obtain 488 experimental single cross hybrids. Subject to availability of adequate seed for evaluation, a panel of 444 experimental single-cross hybrids was evaluated using an augmented design in two experiments defined as Population A and B for the study’s convenience in South African environments. Data for grain yield (t/ha) performance for experimental single-cross hybrids and commercial check hybrids in Population A and B across environments and individual environments identified experimental single-cross hybrids that had significant comparable grain yield (t/ha) performance relative to best commercial check hybrid (PAN6Q445B) on the market. The selected experimental single-cross hybrids 225, 89, 246 and 43 (Population A) and 112 (Population B) also had a better average rank position for grain yield (t/ha) relative to best commercial check hybrid. These selected experimental single-cross hybrids had a grain yield (t/ha) advantage range of 0.9-6.7% for Population A and 7.3% for Population A and B, respectively, relative to the adapted commercial check hybrid. GGE biplot patterns for which won-where for Population A indicated that at Potchefstroom Research Station and Ukulinga Research Station experimental single-cross hybrids 127 and135 were the vertex (winning) hybrids. Cedera Research Station did not have a vertex hybrid for Population A. For Population B, experimental single-cross hybrids 112, 117 and 18 were the vertex hybrids at Cedera Research Station, Ukulinga Research Station and Potchefstroom Research Station, respectively. Experimental single-cross hybrid 257 was identified as ideal genotype for Population A, while experimental single-cross hybrid 121 in Population B was the ideal genotype. Ideal environments were also identified as Ukulinga Research Station for Population A, and Cedera Research Station for Population B. Average-environment coordination (AEC) view of the GGE biplot in Population A indicated that experimental single-cross hybrids 1 was highly stable across environments. In comparison, Population B experimental single-cross hybrid 161 was highly stable across environments. In conclusion, selected single-cross hybrids in the current study can also be advanced for further evaluation with a possibility for identifying high yielding and stable single-cross hybrids for variety registration and release in target environments in South Africa.


1960 ◽  
Vol 40 (2) ◽  
pp. 375-382 ◽  
Author(s):  
Eric D. Putt ◽  
W. E. Sackston

Resistance to aster yellows has been identified in sunflowers. In 560 inbred lines and single plant progenies, 356 showed no symptoms of the disease under field conditions. The others showed infections ranging up to 100 per cent. Six entries, observed at three points, showed a range of infection from 0 to 86 per cent and eighteen others, at two points, a range from 0 to 73 per cent. The behaviour was consistent at the different locations.The resistance to aster yellows appeared to be qualitatively inherited. Single cross hybrids between resistant and, susceptible lines showed the resistance to be dominant. It occurred in association both with susceptibility and with resistance to rust. Of 15 lines with evidence of resistance to leaf mottle disease, 13 lines also had resistance to aster yellows.


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