EPISTASIS IN GRAIN SORGHUM, SORGHUM BICOLOR

1974 ◽  
Vol 16 (4) ◽  
pp. 861-870
Author(s):  
G. H. Liang ◽  
A. D. Dayton ◽  
T. L. Walter

Epistasis, or interaction between nonallelic genes in grain sorghum (S. bicolor (L.) Moench), was estimated by comparing means of 20 balanced sets of single- and 3-way crosses. Each balanced set consisted of three single crosses and three 3-way crosses derived from three of the six parental varieties used. Results indicated that epistasis was present in nine sets for grain yield, in 13 sets for half-bloom date, and in 11 sets for plant height and for kernel weight. Epistasis seemingly fluctuates over years and locations. On the average, 3-way hybrids yielded less grain, flowered later, and were taller than the single-cross hybrids.

2017 ◽  
Vol 16 (3) ◽  
pp. 509 ◽  
Author(s):  
CÍCERO BESERRA MENEZES ◽  
CRISLENE VIEIRA DOS SANTOS ◽  
DOUGLAS CIRINO SALDANHA ◽  
MARCOS PAULO MINGOTE JÚLIO ◽  
KARLA JORGE DA SILVA ◽  
...  

RESUMO - O objetivo do presente trabalho foi selecionar parentais e híbridos de sorgo granífero para características agronômicas. Foram avaliados 184 cruzamentos oriundos de um dialelo parcial envolvendo 16 linhagens macho-estéreis e 12 restauradoras da fertilidade. Foram realizados 8 experimentos, com 23 híbridos cada e duas testemunhas adicionais (BRS 304 e BRS 330), em blocos casualizados, com duas repetições. Foram avaliadas as características rendimento de grãos, florescimento e altura de plantas. Os efeitos de CGC e CEC foram significativos para as três características, mostrando a importância dos efeitos aditivos e dominantes no controle destes caracteres. O quadrado médio para CGC foi superior ao da CEC. Todos os parentais que contribuíram para aumentar o rendimento de grãos também o fizeram para altura de plantas, exceto pelos parentais femininos CMSXS 1006 e CMSXS 1011, mostrando a dificuldade de dissociar estas duas características. Os híbridos mais produtivos apresentaram altura de plantas acima do recomendado para sorgo granífero, mesmo assim foi possível a seleção de cruzamentos que apresentaram rendimento de grãos acima da média, florescimento abaixo da média e altura dentro do padrão exigido. Dentre estes, pode-se destacar os híbridos CMSXS 1002 x CMSXS 1102, CMSXS 1006 x RTx2907, ATx ARG 1 x SC1155 e CMSXS 1008 x Tx2741.Palavras-chave: Sorghum bicolor, seleção de parentais, dialelo, hibridação, melhoramento de plantas. COMBINING ABILITY OF LINES AND SELECTION OF GRAIN SORGHUM HYBRIDS  ABSTRACT - The purpose of this work was to select grain sorghum lines and hybrids for growing as succession crop. Crosses, coming from a partial diallel involving 16 male sterile lines and 12 restorer lines, were evaluated. Eight experiments were carried out with 23 hybrids each and two additional checks (BRS 304 and BRS 330) in randomize complete blocks design, with two replications and plot of two lines of five meters long. Grain yield, days to flowering and plant height were evaluated. The effects of GCA and SCA were significant, showing the importance of both additive and dominant effects in the control of these traits. The mean square for GCA was well above the SCA, suggesting the importance of parental selection in sorghum. Only the lines CMSXS 1006 and CMSXS 1011 contributed to rise grain yield without increasing the plant height in the hybrids they compose. The most productive hybrids showed plants above 150 cm, however it was still possible to get crossings that had yield above average, cycle below average and plant height within the standard required for grain sorghum. Among these are the hybrids CMSXS 1002 x CMSXS 1102, CMSXS 1006 x RTx2907, ATX ARG 1 x SC1155 and CMSXS 1008 x Tx2741, with high yields and CEC.Keywords: Sorghum bicolor, parental selection, diallel, hybridization, crop breeding.


1983 ◽  
Vol 101 (3) ◽  
pp. 669-673 ◽  
Author(s):  
H. A. Esechie

SUMMARYStudies were conducted in two consecutive years at Mead, Nebraska, to investigate the relationship between lodging, certain morphological characters and grain yield of sorghum.Morphological characters correlated with lodging were plant height, length of prepeduncle internode and rind thickness. Lodging was negatively correlated with number of days from sowing to 50% bloom and grain yield but was not correlated with grain weight of the head.


1969 ◽  
Vol 11 (1) ◽  
pp. 199-208 ◽  
Author(s):  
George H. L. Liang ◽  
T. L. Walter ◽  
C. D. Nickell ◽  
Y. O. Koh

Heritability was estimated for 12 agronomic traits in two segregating grain sorghum populations in F3 and F4 generations by parent-offspring regression, parent-offspring correlation, and variance component methods. Half bloom, leaf number, and plant height were most heritable in both populations; head number was least heritable. Grain yield, head weight, kernel number, peduncle diameter, germination percentage, and threshing percentage had medium heritability values. Kernel weight and protein percentage were highly heritable in one population but less heritable in the other.Estimates of genetic correlations showed grain yield positively and strongly correlated with head weight, kernel number, half bloom, leaf number, and plant height, but negatively correlated with germination and protein percentages.Selection indexes constructed using various combinations demonstrated that selecting for yield could be more efficient if combinations other than or in addition to yield were utilized. Selection indexes were less effective in selecting for protein when protein was not included in the index.


1974 ◽  
Vol 54 (2) ◽  
pp. 323-330 ◽  
Author(s):  
F. B. GLENN ◽  
T. B. DAYNARD

Three experiments were conducted near Guelph in 1971 and 1972 with the objectives of studying (1) the effect of planting pattern, plant density, and genotype on plant-to-plant variability in corn (Zea mays L.), and (2) the effect of this variability on grain yield. All three studies entailed detailed measurements of the height of individual plants at various times during vegetative development, and of per plant grain yields. Frequency distributions of individual plant height and grain yield were normal; a coefficient of variability was used to characterize the variation within each treatment. In the first experiment, plant density was found to have a significant effect on plant-to-plant variability in grain yield; row spacing did not affect variation among individuals in either plant height or yield. The second experiment involved study of five double-cross hybrids, five single-cross hybrids, and the 10 possible 50:50 mixtures of the single-cross hybrids. Single-cross hybrids were more uniform and higher yielding than their double-cross counterparts. Mixtures did not vary in yield or variability from the mean of their pure-stand components. In the third experiment, corn was over-planted and differentially thinned in early July (when plants were approximately 60 cm tall) to produce two treatments: uniformly and non-uniformly thinned. Uniformly thinned plots were higher yielding, particularly at a high plant density (103,000 plants/ha). The results lend support to the hypothesis that variability per se can have a significant effect on the grain yield of corn. Reduced variability may represent a partial explanation of the generally higher yield of elite single-cross hybrids over their double-cross counterparts.


1988 ◽  
Vol 28 (3) ◽  
pp. 327
Author(s):  
SR Walker ◽  
WH Hazard ◽  
AF Mich ◽  
BA Silver

Six experiments were conducted in central Queensland to compare the efficacy of some post-emergence herbicides and mixtures in controlling black pigweed (Trianthema portulacastrum) and sesbania pea (Sesbania cannabina). The herbicides tested were atrazine, 2,4-D, dicamba, picloram plus 2,4-D, and fluroxypyr and mixtures of atrazine with 2,4-D, dicamba, picloram plus 2,4-D, fluroxypyr or tridiphane. In addition, 4 experiments were conducted to assess the tolerance of 5 sorghum cultivars (Sorghum bicolor) to some of these individual herbicides and atrazine mixtures. Small black pigweed and sesbania pea (< 10 cm diameter) were controlled with atrazine at 1.0 kg a.i./ ha, while for larger black pigweed (up to 15 cm diameter) atrazine at 2.25 kg/ha and atrazine mixtures were effective and for sesbania pea (up to 12 cm high) atrazine at 2.25 kg/ha, picloram plus 2,4-D at 35 + 140 g a.i./ha, fluroxypyr at 0.3 kg a.i./ha and atrazine mixtures were effective. In general, control of both weeds by mixtures with atrazine at 1.0 kg/ha was as effective as atrazine at 2.25 kg/ha alone. In the tolerance experiments the treatments were applied at 18-20 days after planting when the number of sorghum leaves was 4-6. Spraying with 2,4-D, dicamba, MCPA, picloram plus 2,4-D and atrazine mixtures with 2,4-D, dicamba and picloram plus 2,4-D consistently caused injury symptoms, delayed flowering and sometimes reduced grain yield. However, the susceptibility of sorghum to these treatments varied with seasons and cultivars. Overall, yield reductions were less when 2,4-D, dicamba and MCPA were applied at lower rates in the atrazine mixtures than when applied alone. All sorghum cultivars were tolerant of atrazine at 4.5 kg/ha. For effective control of both weeds, for crop safety and for minimum atrazine residues after harvest, we recommend that the weeds black pigweed and sesbania pea be sprayed when less than 10 cm in diameter or height, respectively, with atrazine at 1.0 kg/ha.


2015 ◽  
Vol 7 (2) ◽  
pp. 1001-1005
Author(s):  
Sushil Kumar ◽  
Pooran Chand

Forty five hybrids derived from a diallel mating design of ten parents and one standard check PUSA CHARI-121 were evaluated for general and specific combining ability effects and standard heterosis for grain yield/plant, dry fodder yield/plant, days to 50 per cent flowering, plant height, number of leaves/plant, leaf length, leaf breadth and 100- seed weight of Sorghum bicolor. The mean square due to general and specific combining ability was significan for Days to 50% flowering, Days to maturity, Plant height (cm),No of Leaves/plant, Leaf length (cm), Leaf width (cm), seed yield/plant (g), Fodder yield/plant (q/ha) and 100-seed weight (g) for all the characters. Both additive and non additive genetic effects were present in the material under study. However the ratio of σ2gca/ σ2sca suggested that the preponderance of non additive gene action in expression of all the characters under study. Out of the nine parents PUSA CHARI-121, PANT CHARI-4, MP CHARI, PANT CHARI-6 and PANT CHARI-5 identified as good general combiner for grain yield/plant, dry fodder yield/plant and other agronomical traits. The hybrid HC-136 x PANT CHARI-4 and PANT CHARI-4 x PUSA CHARI-121 for grain yield/plant and hybrid MP CHARI x PANT CHARI-6, PANT CHARI-5 x SPV 1616 and HC-136 x PANT CHARI-4 for dry fodder yield/plant exhibited higher magnitude of positive significant specific combining ability effect with highest standard heterosis and per se performance. These hybrids were also found suitable for two or three yield contributing traits. In general, close association between specific combining ability effects and standard heterosis was observed among the best hybrids identified on the basis of specific combining ability effects for grain and dry fodder yield.


2009 ◽  
Vol 7 ◽  
pp. 63-69
Author(s):  
PCP Chaurasia ◽  
E Duveiller

An experiment was conducted at agronomy farm of Agriculture research Station, Tarahara,Nepal for three consecutive years viz 2000/2001,2001/2002, and 2002/2003 to evaluate theeffects of different cultural practices on leaf blight diseases of wheat caused by Bipolarissorokiniana under terai conditions. The experiment was conducted in factorial RandomizedComplete Block Design with four replications. Four factors, two wheat verities RR-21 andNepal 297,two number of irrigations (two and three irrigations), two doses of Nitrogen fertilizerviz. 60kg N/ha and 120 kg N/ha and two dates of sowing of wheat were examined. Differentyield components, grain yield (kg/plot) and disease severity were recorded to judge the effects ofthese factors on severity of leaf blight of wheat. Nepal Line 297 had significantly less AUDPCbased on flag leaf infection and whole plan as compared to RR-21. Number of irrigations had nosignificant effect on AUDPC, as there was frequent rain during experimental period. Doses ofNitrogen fertilizer had significant effect on AUDPC based on flag leaf infection. It was higher incase of 60 kg N/ha. The third week of November sowing of wheat had lower value of AUDPCas compared to December sowing. Plant height, panicle lengths were highly significantly higherin case of RR-21 as compared to Nepal-297. Thousand kernel weight, and grain yield kg/ha weresignificantly higher in Nepal-297. All agronomic parameters except thousand kernel weight andnumber of tillers/plan were significantly higher in 120kg N/ha. The third week of Novembersowing of wheat had less plant height and panicle length, higher thousand kernel weight andmore grain yield. Leaf blight severity was highly significantly less in case of Nepal-297. Dosesof Nitrogen fertilizer had significant effect on plant height, panicle length, thousand kernelweight, percentage flag leaf infection and AUDPC based on flag leaf infection. Based on theresults of three years of experimentations, it can be concluded that Nepal-297 had less disease,number of irrigations had no effect on disease severity, higher doses of nitrogen fertilizer hadless flag infection and late sowing of wheat also had less disease. Numbers of irrigation's effectswere inconclusive as there were frequent rains during experimentation period. Based on aboveconclusion, it is recommended that growing wheat verity like Nepal-297, use of higher doses ofnitrogen fertilizer and sowing of wheat / first week of Dec help in minimizing the severity of leafblight. However late sowing had lowered grain yield.Key words: AUDPC; culture practices; disease management; leaf blightDOI: 10.3126/narj.v7i0.1870Nepal Agriculture Research Journal Vol.7 2006 pp.63-69


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&rsquo;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 &times; 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&rsquo;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.


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