scholarly journals Efficiencies of Heterotic Grouping Methods for Classifying Early Maturing Maize Inbred Lines

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1198
Author(s):  
Oyeboade Adebiyi Oyetunde ◽  
Baffour Badu-Apraku ◽  
Omolayo Johnson Ariyo ◽  
Christopher Olusanya Alake
Keyword(s):  
Grain Yield ◽  
Genetic Distance ◽  
Combining Ability ◽  
Diallel Cross ◽  
Hybrid Breeding ◽  
Multiple Traits ◽  
Heterotic Groups ◽  
Maize Hybrids ◽  
Heterotic Grouping ◽  
Additive Gene

The success of a hybrid breeding program is dependent on available heterotic patterns for exploitation of grain-yield heterosis. The efficiency of the assignment of germplasm lines into heterotic groups is a prerequisite for obtaining useful heterotic patterns among germplasm lines. A total of 256 maize hybrids, comprising 244 top crosses, six diallel cross hybrids, and six checks, were grown under Striga infestation, drought, and optimal conditions, from 2015 to 2017. The study determined the combining abilities of the parental inbreds, classified the inbreds into heterotic groups, and compared the efficiencies of the following four grouping methods for classifying the inbreds: specific combining ability (SCA) effect of grain yield; general combining ability (GCA) effects of multiple traits (HGCAMT); SCA and GCA (HSGCA) for yield; and single nucleotide polymorphism-based genetic distance (SNP-based genetic distance (GD)). Significant GCA and/or SCA mean squares were revealed for most measured traits in all test environments. Sums of squares (SS) due to GCA were higher than SCA SS for measured traits in all test environments. The HSGCA, SCA, and SNP-based GD methods identified four heterotic groups, whereas the HGCAMT identified three groups, in all environments. The additive gene effect was preponderant in the inheritance of most measured traits. The efficiencies of the grouping methods varied with the test environments. The HSGCA and SCA methods were the most efficient for grouping in all test conditions. For practical breeding purposes, the HGCAMT and HSGCA methods were recommended under Striga infestation and drought, respectively. The heterotic patterns, which were revealed in this study, were effective for planning hybridization schemes for developing high-yielding, Striga-tolerant/resistant, and drought-tolerant maize hybrids for stressful environments.

scholarly journals Combining ability analysis for yield and yield contributing traits in maize (Zea mays L.)

2019 ◽  
Vol 44 (2) ◽  
pp. 253-259
Author(s):  
HZ Raihan ◽  
S Sultana ◽  
M Hoque
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Combining Ability ◽  
Gene Action ◽  
Diallel Cross ◽  
Grain Weight ◽  
Thousand Grain Weight ◽  
Additive Gene Action ◽  
Additive Gene ◽  
1000 Grain Weight

An experiment on combining ability was carried out with 21 crosses produced from 7×7 diallel cross without reciprocal for grain yield and yield contributing characters in maize. Analysis of variance for combining ability showed that mean square (MS) due to GCA & SCA were highly significant for all characters except GCA in plant height, cob length and 1000 grain weight and SCA in maturity and row/cob indicated that all but mentioned traits were governed by both additive and non-additive gene action. Variances due to GCA were higher for all characters except thousand grain weight revealed that the predominance of additive gene action for all characters except thousand grain weight. Parent CML 487 and Ki 21 were the best general combiner for yield and most of the yield contributing characters. Parent BMZ 57 & BMZ 15 were the best general combiner for dwarf & earliness in plant. Among all the crosses CML 473 × Ki 21, CML 487 × Ki 21 and CML 429 × BIL 182 exhibited significant positive SCA effect for grain yield. The cross CML 429 × BIL 182 may be considered as the best cross with recorded significant mean value and desired SCA for traits like 1000 grain weight, yield (t/ha), days to 50% pollen shedding, days to 50% silking, plant height, ear height and days to maturity. The promising single crosses with significant and positive SCA could be used for variety development after verifying them across locations. Bangladesh J. Agril. Res. 44(2): 253-259, June 2019

scholarly journals Combining Ability and Gene Action of Tropical Maize (Zea mays L.) Inbred Lines under Low and High Nitrogen Conditions

2017 ◽  
Vol 9 (4) ◽  
pp. 222 ◽  
Author(s):  
Mafouasson Apala Hortense Noëlle ◽  
Kenga Richard ◽  
Gracen Vernon ◽  
Yeboah Agyei Martin ◽  
Mahamane Nasser Laouali ◽  
...  
Keyword(s):  
Grain Yield ◽  
Soil Nitrogen ◽  
Combining Ability ◽  
Gene Action ◽  
Inbred Lines ◽  
Hybrid Breeding ◽  
Gene Effect ◽  
Single Cross ◽  
Additive Gene ◽  
Nitrogen Conditions

This study was conducted to determine combining ability and gene action in elite maize inbred lines under low and high soil nitrogen conditions for hybrid breeding. Forty two tropical inbred lines (three testers and 39 lines) were crossed using line × tester mating design. The resulting 117 F1 hybrids, along with 4 hybrids used as checks, were evaluated using an 11 × 11 lattice design with two replications for grain yield and yield related traits during the 2012 and 2013 cropping seasons at two sites (Mbalmayo and Nkolbisson). Results revealed predominant additive gene effect under high soil nitrogen (N) conditions. Non-additive gene effect influenced grain yield under low soil and thus could be exploited for hybrid development. Under high N conditions inbred lines CLYN246, J16-1, CLWN201, TL-11-A-1642-5, CLQRCWQ26 and 1368 were good general combiners. Lines CML 343, ATP S6 20-Y-1, CLWN201, 1368, ATP S9 30 Y-1 and CLQRCWQ26 were good general combiners for grain yield under low N. They could be used to develop low N tolerant varieties. Different single cross hybrid combinations were identified for high grain yields under both low and high N conditions. The selected lines and single cross hybrids are a useful source of valuable genetic material for future maize hybrid breeding or direct production under low N.

scholarly journals Genetic Diversity and Combining Ability of White Maize Inbred Lines under Different Plant Densities

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1140 ◽  
Author(s):  
Mohamed M. Kamara ◽  
Medhat Rehan ◽  
Khaled M. Ibrahim ◽  
Abdullah S. Alsohim ◽  
Mohsen M. Elsharkawy ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Grain Yield ◽  
Genetic Distance ◽  
Combining Ability ◽  
Plant Density ◽  
Inbred Lines ◽  
Hybrid Performance ◽  
High Plant Density ◽  
Plant Densities ◽  
Additive Gene

Knowledge of combining ability and genetic diversity are important prerequisites for the development of outstanding hybrids that are tolerant to high plant density. This work was carried out to assess general combining ability (GCA) and specific combining ability (SCA), identify promising hybrids, estimate genetic diversity among the inbred lines and correlate genetic distance to hybrid performance and SCA across different plant densities. A total of 28 F1 hybrids obtained by crossing eight adverse inbred lines (four local and four exotic) were evaluated under three plant densities 59,500 (D1), 71,400 (D2) and 83,300 (D3) plants ha−1 using spilt plot design with three replications at two locations during 2018 season. Increasing plant density from D1 to D3 significantly decreased leaf angle (LANG), chlorophyll content (CHLC), all ear characteristics and grain yield per plant (GYPP). Contrarily, days to silking (DTS), anthesis–silking interval (ASI), plant height (PLHT), ear height (EHT), and grain yield per hectare (GYPH) were significantly increased. Both additive and non-additive gene actions were involved in the inheritance of all the evaluated traits, but additive gene action was predominant for most traits. Inbred lines L1, L2, and L5 were the best general combiners for increasing grain yield and other desirable traits across research environments. Two hybrids L2 × L5 and L2 × L8 were found to be good specific combiners for ASI, LANG, GYPP and GYPH. Furthermore, these hybrids are ideal for further testing and promotion for commercialization under high plant density. Genetic distance (GD) among pairs of inbred lines ranged from 0.31 to 0.78, with an average of 0.61. Clustering based on molecular GD has effectively grouped the inbred lines according to their origin. No significant correlation was found between GD and both hybrid performance and SCA for grain yield and other traits and proved to be of no predictive value. Nevertheless, SCA could be used to predict the hybrid performance across all plant densities. Overall, this work presents useful information regarding the inheritance of maize grain yield and other important traits under high plant density.

Genetic variation in sorghum as revealed by phenotypic and SSR markers: implications for combining ability and heterosis for grain yield

2016 ◽  
Vol 15 (4) ◽  
pp. 335-347 ◽  
Author(s):  
Beyene Amelework ◽  
Hussien Shimelis ◽  
Mark Laing
Keyword(s):  
Genetic Variation ◽  
Grain Yield ◽  
Ssr Markers ◽  
Combining Ability ◽  
Moisture Stress ◽  
Hybrid Breeding ◽  
Male Sterile ◽  
Heterotic Groups ◽  
Lattice Design ◽  
Sorghum Genotypes

AbstractHybrid breeding relies on selection of genetically unrelated and complementary parents for key traits. The objective of this study was to examine genetic variation and identify unique sorghum genotypes using phenotypic and simple sequence repeat (SSR) markers and to determine their relationships with combining ability and heterosis for grain yield. A total of 32 landraces and four cytoplasmic male sterile (CMS) lines were phenotyped using 25 agro-morphological traits and genotyped with 30 polymorphic SSR markers. The landraces were crossed with four CMS lines using a line × tester mating design. The 128 hybrids, 36 parentals and four check varieties were field-evaluated using a 12 × 14 alpha lattice design with three replications. General combining ability (GCA), specific combining ability (SCA) and heterosis for grain yield were determined. Genetic distance estimates ranged from 0.39 to 0.60 and 0.50 to 0.79, based on phenotypic and SSR markers, respectively. Landraces 72572, 75454, 200654, 239175, 239208, 244735A and 242039B and CMS lines ICSA 743 and ICSA 756 displayed positive and significant GCA effects for grain yield. Based on the SCA effects of yield, lines were classified into three heterotic groups aligned to the different cytoplasmic systems of testers. Lines with high GCA effects rendered hybrids with highly significant SCA effects with high mid-parent heterosis (MPH) for grain yield. Both marker systems were effective in demarcating sorghum genotypes that provided desirable cross-combinations with high combining ability effects and MPH for grain yield. The selected genotypes are recommended as potential parents for sorghum hybrid breeding in moisture stress environments.

scholarly journals Heterosis and combining ability for grain yield and its contributing characters in maize

1970 ◽  
Vol 33 (3) ◽  
pp. 375-379 ◽  
Author(s):  
AKMM Alam ◽  
S Ahmed ◽  
M Begum ◽  
MK Sultan
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Additive Genetic Variance ◽  
Diallel Cross ◽  
Grain Weight ◽  
Combining Ability Analysis ◽  
Days To Maturity ◽  
Additive Gene ◽  
Ear Height ◽  
1000 Grain Weight

Combining ability analysis for grain yield and its contributing characters in maize were carried out in 5×5 diallel cross. The highest percentage of heterosis for grain per ear over mid parent and better parent were observed by the cross P2×P3. Crosses P1×P3 and P1×P5 showed significant negative heterosis for days to maturity. Significant general and specific combining ability variances were observed for all the characters except ear height. Almost equal role of additive and non-additive gene actions was observed for days to maturity. Additive genetic variance was preponderant for grains per ear and 1000-grain weight and non-additive gene action was involved in plant height, ear height, days to silking, and days to maturity. The inbred lines P2 and P5 were found to be best general combiner for 1000-grain weight. Key Words: Heterosis, combining ability, grain yield, maize. doi:10.3329/bjar.v33i3.1596 Bangladesh J. Agril. Res. 33(3) : 375-379, September 2008

Combining ability in the F1 and F2 generations of a diallel cross in six-rowed barley (Hordeum vulgare L.)

2003 ◽  
Vol 51 (3) ◽  
pp. 281-288 ◽  
Author(s):  
Y. Sharma ◽  
S. N. Sharma ◽  
P. Joshi ◽  
R. S. Sain
Keyword(s):  
Hordeum Vulgare ◽  
Grain Yield ◽  
Combining Ability ◽  
Yield Components ◽  
Diallel Cross ◽  
Hordeum Vulgare L ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Additive Gene ◽  
Average Average

The F1 and F2 progenies of a ten-parent diallel cross (excluding reciprocals) were analysed for the combining ability of quantitative traits in six-rowed barley (Hordeum vulgare L.). significant differences were indicated between the parents, F1s and F2s for all the characters studied. The gca and sca components of variance were significant for all the traits. Both additive and non-additive gene effects were involved in the genetic control of the characters; however, non-additive gene effects were observed to be predominant. Among the parents RD 2035, RD 2052, RD 2503 and BL 2 were the best general combiners for grain yield and average to high combiners for other important traits.The parents RD 2552 and RD 387 were the best general combiners for dwarfness. The best specific crosses for grain yield were RD 2503 × RD 2585,RD 2035 × RD 2052, RD 2035 × BL 2, RD 2052 × BL 2, RD 2508 × RD 2552, RD 2552 × RD 2585 and Rd 2052 × RD 2552 in both the F1 and F2 generations. These crosses were higher yielders and in most of the crosses one of the parents involved was a good combiner, indicating that such combinations can be expected to produce desirable transgressive segregants. All the best crosses for grain yield also showed average to high sca effects for most of the yield components. Most of the specific crosses for grain yield involved high × average, average × average and average × poor general combiners. To ensure a further increase in grain yield, the combination of desirable yield components is advocated. The inclusion of F1 hybrids showing high sca, and having parents with good gca, in multiple crosses, bi-parental mating or diallel selective mating could prove a worthwhile approach for further amelioration of grain yield in six-rowed barley.

scholarly journals Combining ability and heterosis on yield and its component traits in maize (Zea mays L.)

2016 ◽  
Vol 41 (3) ◽  
pp. 565-577 ◽  
Author(s):  
MZA Talukder ◽  
ANM S Karim ◽  
S Ahmed ◽  
M Amiruzzaman
Keyword(s):  
Combining Ability ◽  
Diallel Cross ◽  
Kernel Weight ◽  
Early Maturity ◽  
Ecological Zones ◽  
Component Traits ◽  
Additive Gene ◽  
Positive Heterosis ◽  
Half Diallel ◽  
Kernel Yield

Combining ability and heterosis were studied in a 7×7 half diallel cross in maize for grain yield and yield contributing characters. Significant general and specific combining ability variances were observed for all the characters studied. The significant estimates of GCA and SCA variances suggested the importance of both additive and non-additive gene actions for the expression studied traits. In these studies, variances due to SCA were higher than GCA for all charactesr, which revealed the predominance of non additive gene action (dominance and epistasis) for controlling these traits. Parents P1 and P4 were excellent general combiner for days to tasseling and silking while P1 and P5 for early maturity. P4 for short height and, P4 and P7 for higher thousand kernel weight. The parents P4 and P6 having good combining abilities for yield. Heterosis estimation was carried out using two commercial varieties NK40 and 900MG. When standard commercial check NK40 was used, the percent heterosis for kernel yield varied from -51.39 to 12.53%. Among the 21 F1s, 3crosses exhibited significant positive heterosis for kernel yield. The highest heterosis was exhibited by the cross P4×P6 (12.43%), P6×P7 (10.89%) and P2×P3 (9.87%) respectively. Compared with 900MG as check, the percent heterosis for kernel yield varied from -53.73 to 7.01%. Among the 21 F1s, none of the crosses exhibited significant positive heterosis for kernel yield. The highest heterosis were exhibited by the crosses P4×P6 (7.01%), P6 x P7 (5.55%) and P2×P3 (4.57%). The crosses showed significant positive SCA values could be used for variety development after verifying them across the agro-ecological zones of Bangladesh.Bangladesh J. Agril. Res. 41(3): 565-577, September 2016

scholarly journals Genetic parameters and combining ability of some important traits in rice (Oryza sativa L.)

Genetika ◽  
2017 ◽  
Vol 49 (3) ◽  
pp. 1001-1014 ◽  
Author(s):  
Hasanalideh Haghighi ◽  
Ezatollah Farshadfar ◽  
Mehrzad Allahgholipour
Keyword(s):  
Combining Ability ◽  
Genetic Parameters ◽  
Amylose Content ◽  
Oryza Sativa L ◽  
Block Design ◽  
Regression Line ◽  
Diallel Cross ◽  
Combining Ability Analysis ◽  
Additive Gene ◽  
F2 Generation

In order to study the combining ability, genetic parameters and gene actions of yield, yield components and quality characters in rice, fifteen F2 generation of a 6?6 diallel cross, excluding reciprocals, was grown in a randomized complete block design (RCBD) with three replications. The results of analysis of variance showed significant differences between the genotypes for grain yield (GY), 100-grain weight (HGW), number of panicles per plant (PN), panicle length (PL), number of full grains per panicle (FGN) and for quality characters including amylose content (AC) and gel consistency (GC). The results of combining ability analysis revealed that general combining ability (GCA) and specific combining ability (SCA) were significant for characters GY, FGN, GC, AC, HGW and PN indicating the involvement of additive and non-additive effects in their inheritance, however high amounts of Bakers ratio remarked that additive gene effect had more portion in controlling these traits. The best combiners for GY, HGW, FGN, PN and PL, were RI18447-2, IR 50, Daylamani, RI18430-46 and Daylamani respectively. For AC and GC, the best combiner was Daylamani. Hayman's graphs showed that regression line passed below the origin cutting Wr axis in the negative region for HGW, PN, PL and GC, indicating the presence of over dominance. Estimates of genetic parameters showed significant amount of H1 and H2, and non-significant amount of D for the characters GY, PN, PL and GC, which confirmed the existence of dominance in the inheritance of these traits.

scholarly journals Combining ability and heritability of selected rice varieties for grain yield, its components and grain quality characters

Genetika ◽  
2015 ◽  
Vol 47 (2) ◽  
pp. 559-570 ◽  
Author(s):  
Mehrzad Allahgholipour ◽  
Ezatollah Farshdfar ◽  
Babak Rabiei
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Grain Quality ◽  
Amylose Content ◽  
Gelatinization Temperature ◽  
Narrow Sense ◽  
Rice Varieties ◽  
Narrow Sense Heritability ◽  
Head Rice ◽  
Additive Gene

This study was conducted to determine the combining ability and heritability of rice grain yield, its components and some grain quality traits such as amylose content (AC), gelatinization temperature (GT), gel consistency (GC) and head rice recovery (HRR). The study was commenced by crossing the selected rice varieties based on a full diallel mating design. The F1 was harvested at the end of the season. In the following season, the crossed, reciprocal and parental lines were planted in randomly complete block design with three replications. Analysis of variance indicated that genotypes were significantly different for all traits. The diallel analysis by Griffing`s method showed highly significant differences for GCA for number of panicles per plant (PN), amylose content, gelatinization temperature and head rice recovery. Highly significant differences were also observed for both SCA and REC for all evaluated characters. The results showed that the grain yield (GY), number of filled grains (FGN), 100-grain weight (HGW) and GC were controlled by non-additive gene action, while the inheritance of PN, AC, GT and HRR were largely controlled by additive gene effects, although non- additive genetic components and reciprocal effect were also involved, which suggest that a selection process could be done in the early generations. The two improved lines (RI18442-1 and RI18430-46) were found to be good general combiners for GY and FGN, while the best combiners for PN was Tarom Mohali and IR50 and for HGW was RI18430-46. The best combinations for GY were RI18430-46 ? IR50, Tarom Mohali ? RI18447-2 and Daylamani ? RI18430-46. The good hybrids were Tarom Mohali ? IR50, Line23 ? RI18447-2 and Line23 ? Backcross line for AC. Narrow sense heritability showed that the GY and GC had the lowest values while the other traits had either moderate or high heritability, which indicates selection in the early generations could be done to fix the favorable genes. In present study, narrow sense heritability was high for AC and moderate for GT, PN and HRR.

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