scholarly journals ANALYSIS OF CORRELATION AND AGRO-MORPHOLOGICAL TRAITS IN SINGLE CROSS HYBRIDS OF MAIZE

2021 ◽  
Vol 117 (9) ◽  
pp. 143-149
Author(s):  
H.P. Sharma ◽  
J. Upadhyaya ◽  
J. Shrestha
Keyword(s):  
Morphological Traits ◽  
Single Cross ◽  
Single Cross Hybrids

scholarly journals Stability Assessment of Single-Cross Maize Hybrids Using GGE-Biplot Analysis

2021 ◽  
Vol 13 (2) ◽  
pp. 78
Author(s):  
L. Musundire ◽  
J. Derera ◽  
S. Dari ◽  
A. Lagat ◽  
P. Tongoona
Keyword(s):  
Grain Yield ◽  
South African ◽  
Inbred Line ◽  
Inbred Lines ◽  
Yield Potential ◽  
Research Station ◽  
Gge Biplot ◽  
Single Cross ◽  
Ideal Genotype ◽  
Single Cross Hybrids

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.

RESISTANCE OF INBRED LINES AND HYBRIDS OF SUNFLOWERS (HELIANTHUS ANNUUS L.) IN A NATURAL EPIDEMIC OF ASTER YELLOWS

1960 ◽  
Vol 40 (2) ◽  
pp. 375-382 ◽  
Author(s):  
Eric D. Putt ◽  
W. E. Sackston
Keyword(s):  
Helianthus Annuus ◽  
Inbred Lines ◽  
Field Conditions ◽  
Single Plant ◽  
Aster Yellows ◽  
Helianthus Annuus L ◽  
Single Cross ◽  
Single Cross Hybrids

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.

Assessment of tomato source breeding material through mating designs

2007 ◽  
Vol 146 (3) ◽  
pp. 301-310 ◽  
Author(s):  
M. S. KOUTSIKA-SOTIRIOU ◽  
E. A. TRAKA-MAVRONA ◽  
G. L. EVGENIDIS
Keyword(s):  
Combining Ability ◽  
Source Material ◽  
Plant Performance ◽  
Breeding Value ◽  
Population Bottlenecks ◽  
Plant Selection ◽  
Single Cross ◽  
High Yielding Varieties ◽  
Founder Events ◽  
Single Cross Hybrids

SUMMARYCultivated tomato has a narrow germplasm base because of several population bottlenecks in the form of founder events, as well as natural and artificial selections that occurred during domestication and evolution of modern cultivars. The F2 of commercial single-cross hybrids, as well as locally well-adapted varieties, provide germplasm for developing recombinant lines and exploiting genetic variability, respectively. The present study aims to discriminate the breeding value of tomato source material, i.e. commercial hybrids or well-adapted varieties, by (i) estimating tolerance to inbreeding of hybrids or estimating heterosis of diallel hybrids between varieties, (ii) determining undesirable traits and (iii) determining general combining ability (GCA) and specific combining ability (SCA) effects from diallel crosses between hybrids and between varieties. Two hybrids and four varieties were assessed. One hybrid showed 0·03 inbreeding vigour, which was not combined with undesirable traits in the F2 generation. However, negative GCA and positive SCA values did not support the hybrid as source material, provided that hybrids with low inbreeding depression, positive GCA and negative SCA correspond to an F2 capable of developing recombinant lines. The assessment of the varieties showed positive GCA and 0·34 heterosis in one variety, indicating agreement between yield and GCA, and that high-yielding varieties may produce high-yielding hybrids. In conclusion, the proposed mating design, taking into account the tolerance to inbreeding for hybrids and the heritability of general worth for both resources, provides a mechanism for ensuring continued improvement in plant performance through plant selection programmes.

scholarly journals Prediction of Maize Single Cross Hybrids Using the Total Effects of Associated Markers Approach Assessed by Cross-Validation and Regional Trials

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Wagner Mateus Costa Melo ◽  
Renzo Garcia Von Pinho ◽  
Marcio Balestre
Keyword(s):  
Training Trial ◽  
Cross Validation ◽  
Predictive Accuracy ◽  
Field Performance ◽  
Training Population ◽  
Maize Hybrids ◽  
Single Cross ◽  
The Cross ◽  
Predictive Validation ◽  
Single Cross Hybrids

The present study aimed to predict the performance of maize hybrids and assess whether the total effects of associated markers (TEAM) method can correctly predict hybrids using cross-validation and regional trials. The training was performed in 7 locations of Southern Brazil during the 2010/11 harvest. The regional assays were conducted in 6 different South Brazilian locations during the 2011/12 harvest. In the training trial, 51 lines from different backgrounds were used to create 58 single cross hybrids. Seventy-nine microsatellite markers were used to genotype these 51 lines. In the cross-validation method the predictive accuracy ranged from 0.10 to 0.96, depending on the sample size. Furthermore, the accuracy was 0.30 when the values of hybrids that were not used in the training population (119) were predicted for the regional assays. Regarding selective loss, the TEAM method correctly predicted 50% of the hybrids selected in the regional assays. There was also loss in only 33% of cases; that is, only 33% of the materials predicted to be good in training trial were considered to be bad in regional assays. Our results show that the predictive validation of different crop conditions is possible, and the cross-validation results strikingly represented the field performance.

scholarly journals Performance of irrigated green corn cultivars in different plant populations at sowing

2017 ◽  
Vol 21 (4) ◽  
pp. 267-272
Author(s):  
José C. Soares Neto ◽  
Antônio L. dos Santos Neto ◽  
Wellington M. dos Santos ◽  
Daline T. S. Barros ◽  
Ademária A. de Souza ◽  
...  
Keyword(s):  
Photosynthetic Rate ◽  
Block Design ◽  
Plant Populations ◽  
Corn Hybrids ◽  
Corn Production ◽  
Experimental Area ◽  
Randomized Complete Block Design ◽  
Single Cross ◽  
The City ◽  
Single Cross Hybrids

ABSTRACT This study aimed to evaluate the yield of green corn hybrids grown under irrigation in different plant populations at sowing. The assay was carried out in the experimental area located in the city of Arapiraca, Alagoas State, Brazil, from November 2015 to January 2016. A randomized complete block design (RCBD) was used, in a 2 x 5 factorial scheme with four replicates. A double- and a single-cross hybrid (AG 1051 and BM 3061), which are suitable for green corn production, were cultivated in five spacings between plants at sowing (15.0, 17.5, 20.0, 22.5 and 25.0 cm). The characteristics photosynthetic rate (PR), ear length with rusk (HEL) and without husk (UEL), husked ear weight (HEW), unhusked ear weight (UEW), percentage of marketable ears (%ME) and weight of husk (HW) were evaluated. The double- and single-cross hybrids AG 1051 and BM 3061 showed green ears with commercial standard. The cultivar BM 3061 showed the best results for most of the characteristics related to the performance of green corn (PR, HEL, UEL, UEW, HEW, %ME). The spacing of 17.5 cm between plants at sowing was the most indicated for irrigated green corn cultivation.

scholarly journals Performance of testers with different genetic structure for evaluation of maize inbred lines

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 ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Combining Ability ◽  
Genetic Variance ◽  
Inbred Lines ◽  
General Combining Ability ◽  
Specific Combining Ability ◽  
Genetic Base ◽  
Maize Inbred Lines ◽  
Single Cross ◽  
Single Cross Hybrids

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.

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