Modelling the Effects on Grain Yield of Genetic Variation in Some Crop Characteristics

1985 ◽  
pp. 157-164
Author(s):  
R. B. Austin
2011 ◽  
Vol 91 (1) ◽  
pp. 37-48 ◽  
Author(s):  
M. Cogliatti ◽  
F. Bongiorno ◽  
H. Dalla Valle ◽  
W J Rogers

Fifty-seven accessions of canaryseed (47 populations and 10 cultivars) from 19 countries were evaluated for agronomic traits in four field trials sown over 3 yr in the province of Buenos Aires, Argentina. Genetic variation was found for all traits scored: grain yield and its components (grain weight, grain number per square meter, grain number per head and head number per square meter), harvest index, percent lodging, and phenological characters (emergence to heading, emergence to harvest maturity and heading to harvest maturity). Although genotype × environment interaction was observed for all traits, the additive differences between accessions were sufficient to enable promising breeding materials to be identified. Accessions superior in performance to the local Argentinean population, which in general gave values close to the overall mean of the accessions evaluated, were identified. For example, a population of Moroccan origin gave good yield associated with elevated values of the highly heritable character grain weight, rather than with the more commonly observed grain number per square meter. This population was also of relatively short stature and resistant to lodging, and, although it performed best when sown within the normal sowing date, tolerated late sowing fairly well. Other accessions were also observed with high grain weight, a useful characteristic in itself, since large grains are desirable from a quality point of view. Regarding phenology, the accessions showed a range of 160 degree days (8 calendar days in our conditions) in maturity, which, while not large in magnitude, may be of some utility in crop rotation management. Some accessions were well adapted to late sowing. Grain yield in general was strongly correlated with grain number per square meter. Principal components analysis (PCA) carried out for all characteristics provided indications of accessions combining useful characteristics and identified three components that explained approximately 70% of the phenotypic variation. Furthermore, a second PCA plus regression showed that approximately 60% of the variation in grain yield could be explained by a component associated with harvest index and grain number per square meter. Pointers were provided to possible future breeding targets.Key words: Phalaris canariensis, canaryseed, accessions, yield, phenology, genetics, breeding


2021 ◽  
Author(s):  
Yun Luo ◽  
Mingliang Zhang ◽  
Yu Liu ◽  
Jie Liu ◽  
Wenqiang Li ◽  
...  

2019 ◽  
Vol 48 (3) ◽  
pp. 521-527
Author(s):  
Muhammad Sajjad Iqbal ◽  
Abdul Ghafoor ◽  
Muhammad Akbar ◽  
Shamim Akhtar ◽  
Sammer Fatima ◽  
...  

Thirty two genotypes of Nigella sativa L. were evaluated for three consecutive years which showed significant differences for all the traits indicating high level of genetic variation. Heritability in broad sense ranged from 0.28 to 0.98 and the highest heritability was calculated for days to maturity and days to flowers. Grain yield was positively associated with plant height, capsule weight, capsule length, root length, whereas negatively with capsule width and 1000-seed weight that required the use of novel breeding techniques to break this undesired linkage to improve grain yield in N. sativa. Path coefficient indicated that direct effects of all the traits were positive except days to first flower, days to 50% flowers, flowering duration, number of capsules, root weight and harvest index. The characters exhibiting correlation along with direct effect towards grain yield viz., days to maturity, capsule weight, capsule length and root length should be given more preference while selecting high yielding N. sativa genotypes for future crop improvement programs.


2019 ◽  
Vol 71 (4) ◽  
pp. 1614-1627 ◽  
Author(s):  
Giovanni Melandri ◽  
Ankush Prashar ◽  
Susan R McCouch ◽  
Gerard van der Linden ◽  
Hamlyn G Jones ◽  
...  

Abstract Drought-stressed plants display reduced stomatal conductance, which results in increased leaf temperature by limiting transpiration. In this study, thermal imaging was used to quantify the differences in canopy temperature under drought in a rice diversity panel consisting of 293 indica accessions. The population was grown under paddy field conditions and drought stress was imposed for 2 weeks at flowering. The canopy temperature of the accessions during stress negatively correlated with grain yield (r= –0.48) and positively with plant height (r=0.56). Temperature values were used to perform a genome-wide association (GWA) analysis using a 45K single nucleotide polynmorphism (SNP) map. A quantitative trait locus (QTL) for canopy temperature under drought was detected on chromosome 3 and fine-mapped using a high-density imputed SNP map. The candidate genes underlying the QTL point towards differences in the regulation of guard cell solute intake for stomatal opening as the possible source of temperature variation. Genetic variation for the significant markers of the QTL was present only within the tall, low-yielding landraces adapted to drought-prone environments. The absence of variation in the shorter genotypes, which showed lower leaf temperature and higher grain yield, suggests that breeding for high grain yield in rice under paddy conditions has reduced genetic variation for stomatal response under drought.


1997 ◽  
Vol 48 (5) ◽  
pp. 605 ◽  
Author(s):  
M. A. Fabrizius ◽  
M. Cooper ◽  
K. E. Basford

Grain yield and protein concentration are two of the more important criteria for wheat breeding in Queensland. Three aspects of the inheritance of both of these traits can have an impact on achieving genetic progress: (i) the magnitude and form of the genetic correlation between the traits, (ii) the magnitude of genetic variation and genotype × environment interactions, and (iii) the importance of epistasis in genetic variation. These 3 factors were examined for 2 crosses in a multi- environment trial conducted in Queensland in 1989. Negative genetic correlations were found between grain yield and protein concentration in both crosses. Genetic variation and genotype × environment interactions were found to be important for both traits. There was little evidence for the existence of significant additive × additive epistasis for either trait and the genotype × environment interactions were predominantly additive × environment in nature. From both crosses, progeny combining the high yield and high protein levels of the parents were identified. This suggests that there was a degree of independent segregation of the genes controlling grain yield and protein concentration in both crosses. Therefore, simultaneous genetic progress for yield and protein concentration is possible in Queensland environments.


1984 ◽  
Vol 103 (3) ◽  
pp. 543-547 ◽  
Author(s):  
S. Singh ◽  
M. S. Dahiya

SummaryThe data obtained from 360 progeny families produced by crossing 40 F2 plants from each of three wheat crosses HD 2009 × HD 1949, Raj 821 × WH 147 and NP 876 × HD 1949, to three testers (the testers being the two parents of each original cross and their F1 in each case) were subjected to triple test cross analysis for detecting and estimating additive, dominance and epistatic components of genetic variation and interaction of these components with environment for plant height, spike length, number of tillers per plant, number of spikelets per spike, number of grains per spike, 1000-grain weight, number of days from sowing to heading and to maturity, grain yield per plant and grain yield/above ground dry matter ratio (harvest index). Epistasis was an important element for plant height, number of tillers per plant, number of grains per spike and grain yield per plant in all three crosses. Both the i type and j and l type epistasis were equally important. In general, the magnitude of additive component was larger than that of dominance component. The additive gene effects were more sensitive to environmental change than the dominance gene effects. Similarly, j and l type epistasis was relatively more sensitive to environment than the i type epistasis.


2006 ◽  
Vol 86 (3) ◽  
pp. 723-726 ◽  
Author(s):  
A. Navabi ◽  
M. Iqbal ◽  
K. Strenzke ◽  
D. Spaner

We examined the genetic variation for lodging tolerance in different plant height groups, within a diverse population of wheat (Triticum aestivum L.) genotypes (n = 14 0). Lodging was artificially induced by dragging a weighted apparatus across plots twice during the season at early and late milk stages. Grain yield was negatively correlated with lodging, while lodging scores were positively correlated with plant height. Although plant height appeared to be the major contributor to lodging tolerance, some variation was also observed in taller plants. This suggests that genetic gain in lodging tolerance can be obtained, to some extent, independent of plant height. Key words: Plant height, lodging tolerance, Triticum aestivum L., CIMMYT, Canada


2015 ◽  
Vol 397 (1-2) ◽  
pp. 213-225 ◽  
Author(s):  
M. Liakat Ali ◽  
Jon Luetchens ◽  
Josiel Nascimento ◽  
Timothy M. Shaver ◽  
Greg R. Kruger ◽  
...  

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