Heterotic groups for identifying of suitable combiners in sunflower using top-cross

2021 ◽  
pp. 9-22

The study was conducted in order to identify the suitable parental inbred lines using top cross method for improvement of new sunflower F1 single cross hybrids at research field of Seed and Plant Improvement Institute in Karaj, Iran during two Crop season (2018 and 2019). Experimental materials consisted of 31 restore lines and 43 cytoplasmic male sterile lines which were crossed with A1221 and R14 as the testers respectively. The developed F1 hybrids were evaluated for GCA of three breeding objectives i.e. flowering time, plant height and grain yield during two years replicated trials. Cluster analysis revealed two heterotic groups in which the restorer lines; R22, R24 and R38 (Grain yield of 33, 32 and 31 g head-1 respectively) and three CMS lines; A32, A370 and A110 (Grain yield of 47, 44 and 43 g head-1 respectively) were identified as the suitable restorer and cytoplasmic male sterile line for improvement of new sunflower single cross hybrids. Evaluation of specific combing ability of the resulted combinations will reveal the efficiency of this selection in the following generation.

1969 ◽  
Vol 62 (2) ◽  
pp. 156-164
Author(s):  
A. Sotomayor-Ríos ◽  
D. E. Weibel

Seven grain sorghum lines (Sorghum bicolor (L.) Moench) selected from the Sorghum Conversion Program (SCP) and their F1 hybrids from crosses with CK-60, Martin, and Redlan were evaluated. Days to midflower, height, rust (Puccinia purpurea Ckd.) reaction, number of heads/plot, test weight, threshing percentage, and grain yield were rated or measured. The seven lines when selfed were, in general, the latest to reach midf lower. Four height groups were observed; the taller hybrids were the result of the complementary effect of different height factors in the parents. Rust ratings ranged from 2.9 to 4.9; F1 hybrids Martin x 4, Martin x 7, and Redlan x 7 were the most susceptible to rust. Generally, sorghums with a high grain yield also had a high test weight and thresh ing percentage. The grain yield ranged from 1,866 to 4,261 kg/ha. Mean yields were, on the average, 26% higher for F1 hybrids than for their respective male parents. A 67% heterosis for grain yield was observed in two crosses invo lving Martin and Redlan female parents.


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.


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.


1973 ◽  
Vol 53 (4) ◽  
pp. 783-789 ◽  
Author(s):  
B. R. CHRISTIE

Single-cross hybrids of orchard grass (Dactylis glomerata L.) were evaluated for yield, in vitro digestibility (IVD), and relative maturity in three trials. All trials were planted broadcast, using seed produced on male-sterile clones. All trials were harvested for 2 yr. The average yield of the 48 hybrids tested was 98% of that for the cultivar Frode in the first cut each year, and 103% over the season. The most productive hybrid produced 28% more forage than Frode in the first cut, and 15% more over the season. For IVD, there was no evidence of hybrid superiority. The results indicate that the use of hybrids can result in an increase in forage yield.


2018 ◽  
Author(s):  
Vikrant Tyagi ◽  
Gurpreet Kaur ◽  
Prashant Kaushik ◽  
Satwinder Kaur Dhillon

Abstract:Sunflower is sensitive to drought and its hybrids have a limited cytoplasmic diversity. The wild cytoplasmic sources of sunflower are not well exploited to their potential for drought tolerance and hybrid development. In this respect, we carried out a Line × Tester based genetic study using 19 sunflower genotypes representing, 13 cytoplasmic male sterile (CMS) lines from wild and conventional sources, 2 maintainer lines, and 4 restorer lines. The CMS and maintainer lines were crossed with restorer lines to develop sixty one-way F1 hybrids. The parents and their hybrids were evaluated under two water regimes viz., normal irrigated and water stress. A total of twelve important plant descriptors were studied over a period of two years. The significant differences were observed between parents and hybrids in both water regimes. Hybrids were higher in average values for all the descriptors than parents. The role of female parent was more prominent in the expression of traits in hybrids as compared to male parents. The CMS sources varied significantly regarding seed yield per plant and other physiological traits. Proline content was three times higher in parents and their hybrids under water stress, and it was not correlated with any other descriptor. Accession CMS-PKU-2A was identified as the best general combiner for leaf area and specific leaf weight. Whereas, CMS-234A was the best general combiner for biological yield and photosynthetic efficiency under both the conditions. The cross combinations CMS-ARG-2A × RCR-8297, CMS-234A × P124R, and CMS-38A × P124R were found significant for biological yield, seed yield and oil content under both environments. Overall, this study provides useful information about the cytoplasmic effects on important sunflower traits and drought stress tolerance when used in the different combinations.


Zuriat ◽  
2015 ◽  
Vol 16 (1) ◽  
Author(s):  
D. Ruswandi ◽  
N. Wicaksana ◽  
M. Rachmadi ◽  
A. Ismail ◽  
D. Arief ◽  
...  

Improvement of high yield maize cultivars possessing high quality of seed as showed by high lysine and tryptophan content must be fulfilled with resistance against downy mildew pathogen in any maize breeding program. A set of experiment to study genetic variability and to estimate both heritability and heterosis of important characters of grain yield on DMR and QPM lines has been conducted. Four downy mildew resistance (DMR) lines, i.e. Nei 9008, P 345, Ki 3, and MR 10; three quality protein maize (QPM) lines, including CML 161, CML 163, and CML 172; and their single cross hybrids formed based on line × tester mating design were used in the experiment. The following characters: height of the first ear, seeds number per row, seed weight per ear, and grain yield per plot showed broad genetic variability. Narrow sense heritability (hns) of grain yield and its components ranged from 0.01 to 0.71. Broad sense heritability (hbs), on the other hand, ranged from 0.20 to 0.74. It was found that hybrid derived from crossing between parental inbred lines possessing broad genetic background would express high heterosis.


Genetika ◽  
2012 ◽  
Vol 44 (2) ◽  
pp. 399-408 ◽  
Author(s):  
Snezana Mladenovic-Drinic ◽  
Marija Kostadinovic ◽  
Danijela Ristic ◽  
Milan Stevanovic ◽  
Zoran Camdzija ◽  
...  

The yield, grain yield heterosis and genetic distance based on SSR markers were analyzed in eight maize hybrids and their parental lines. The mean grain yield of all F1 hybrids was 11.37 tha-1. The F1 hybrid from the crosses between L4xL6 gave the highest grain yield of 12.12 tha-1. For the mid parent heterosis (MPH) grain yields of the F1 hybrids, the data showed the average value of 164.25%, and ranged from 136.72% (L4xL6) to 218.07% (L8xL2), and for better parent heterosis (BPH) from 100.70% (H4) to 212.60% (H2), averaged 137.36%. The average genetic distance among parental inbred lines of analyzed hybrids was 0.58 with a range from 0.55 to 0.61. The GD showed a positive correlation with the grain yield of the F1 hybrids (0.22), as well as with MPH and BPH, with the values of 0.12 and 0.45, respectively.


2019 ◽  
Vol 33 (6) ◽  
pp. 776-796
Author(s):  
Gloria Boakyewaa Adu ◽  
Baffour Badu-Apraku ◽  
Richard Akromah ◽  
Alidu Haruna ◽  
Isaac Kodzo Amegbor ◽  
...  

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