EVALUATION OF THE INBRED–BACKCROSS METHOD FOR STUDYING THE GENETICS OF CONTINUOUS VARIATION

1978 ◽  
Vol 58 (1) ◽  
pp. 7-12 ◽  
Author(s):  
R. J. BAKER

The inheritance of kernels per spike was studied in 73 inbred–backcross lines from the second backcross of Pitic 62 spring wheat to Neepawa. Data from two four-replicate experiments failed to show any evidence of influence by major genes. Similarly, kernel weight data from 91 inbred–backcross lines from the second backcross of Glenlea to Neepawa failed to show any influence of major genes. It is suggested that the inbred–backcross technique of Wehrhahn and Allard (1965) is of limited value in studying the genetics of quantitative traits except where the distribution of line performances is discontinuous.

1972 ◽  
Vol 14 (3) ◽  
pp. 667-673 ◽  
Author(s):  
B. S. Talukdar

The inbred backcross line method was used to study the genetics of the difference in seed weight between two hard red spring wheat cultivars, Thatcher and Selkirk. Three major genes, one with large and two with relatively small but equal effects, were found to control the difference. The distribution of the alleles was unidirectional with Thatcher carrying the alleles for light and Selkirk carrying the alleles for heavy seed. Linkage, dominance, and epistasis caused practically no bias in the analysis. The result indicates that breeding for seed weight should be simple.


1975 ◽  
Vol 17 (3) ◽  
pp. 433-439 ◽  
Author(s):  
K. K. Wu ◽  
F. W. Sosulski ◽  
C. F. Wehrhahn

Genie analysis was used to study the inheritance of sedimentation value and protein content in two sets of reciprocal inbred backcross lines. Three loci containing genes with major effects were responsible for most of the differences in sedimentation value between two wheat cultivars, Baart and Ramona, grown in two years. These loci accounted for 84% to 93% of genetic variation, while environmental variances were relatively low. However, the differences in protein content between the two parents were too small for the present technique to detect the presence of any major genes. No genetic relationship was found between protein content and sedimentation value.


2021 ◽  
pp. 1-13
Author(s):  
Showkat A. Zargar ◽  
Aijaz A. Wani ◽  
M. I. S. Saggoo

Abstract Apricot (Prunus armeniaca L.) is a world-wide highly appreciated fruit, with its attractive colour, soft texture and typical flavour. In the current investigation, 68 apricot accessions collected from Jammu and Kashmir, India were analysed to determine the measure of variation using 12 qualitative and 16 quantitative traits with an aim to identify superior apricot accessions with excellent fruit quality traits. High phenotypic variability was observed among the studied apricot accessions with significant differences among most of the qualitative and quantitative traits. Fruit-related characteristics including fruit weight, fruit length, fruit ratio, fruit firmness, fruit shape, fruit suture, stone weight, kernel weight and stone shape were the most diverse with a high coefficient of variation (>30%). One way analysis of variance showed significant differences (P < 0.0001) among all the quantitative traits. Significant positive and negative correlations were observed between all the agronomically important fruit quality traits. The principal component analysis (PCA) revealed that 75.34% of the variability was defined by the first eight components. The unweighted pair group method with arithmetic mean (UPGMA) dendrogram, based on all traits measured grouped the accessions into two main clusters with several sub-clusters. Both UPGMA dendrogram and PCA scatter plot formed a cluster of 14 accessions, having the highest values regarding most important fruit quality traits such as fruit weight, fruit length and width, fruit ratio, stone weight and kernel weight can be treated as potentially superior accessions. These accessions can be used directly for cultivation and in future apricot breeding programmes. The present findings are promising for genetic resource management, cultivar improvement and commercial applications of apricot in Jammu and Kashmir, India.


Author(s):  
Andrew James Burt ◽  
D.G. Humphreys ◽  
J. Mitchell Fetch ◽  
Denis Green ◽  
Thomas Fetch ◽  
...  

AAC Redstar is an early maturing, high yielding hard red spring wheat (Triticum aestivum L.) cultivar that is well adapted to the northern Canadian Prairies and eligible for grades of Canada Western Red Spring (CWRS) wheat. Over three years (2016-2018) of testing in the Parkland Wheat Cooperative registration trials, AAC Redstar was 11% higher yielding than AC Splendor, 6% higher than Parata, and 4% higher than Glenn and Carberry. AAC Redstar matured 3 days earlier than Glenn, 2 days earlier than Carberry and had similar maturity to Parata. AAC Redstar was shorter than all checks except Carberry and had better lodging resistance compared to all the check cultivars in the registration trial. The test weight and thousand kernel weight of AAC Redstar were similar to Carberry. The grain protein concentration of AAC Redstar was 0.2% lower than Carberry. AAC Redstar was rated moderately resistant to Fusarium head blight, leaf rust, stripe rust and common bunt. AAC Redstar had resistant reactions to loose smut, and stem rust. AAC Redstar was registered under the CWRS market class.


2015 ◽  
Vol 95 (4) ◽  
pp. 615-627 ◽  
Author(s):  
Hiroshi Kubota ◽  
Sylvie A. Quideau ◽  
Pierre J. Hucl ◽  
Dean M. Spaner

Kubota, H., Quideau, S. A., Hucl, P. J. and Spaner, D. M. 2015. The effect of weeds on soil arbuscular mycorrhizal fungi and agronomic traits in spring wheat (Triticum aestivum L.) under organic management in Canada. Can. J. Plant Sci. 95: 615–627. Understanding the influence of weeds in agroecosystems may aid in developing efficient and sustainable organic wheat production systems. We examined the effect of weeds on soil microbial communities and the performance of spring wheat (Triticum aestivum L.) under organic management in Edmonton, AB, Canada. We grew 13 Canadian spring wheat cultivars in organically managed hand-weeded less-weedy and weedy treatments in 2010 and 2011. The less-weedy treatment exhibited greater grain yield and tillers per square meter, while kernel weight, test weight, days to maturity, plant height, grain P and protein content were not altered by weed treatment. Canada Western Red Spring (CWRS) wheat cultivars CDC Go and CDC Kernen were the most yield-stable because they minimized fertile tiller reduction in response to weed pressure (10 and 13% reduction, respectively, compared with the average reduction of 20%). Other cultivars exhibited yield stability through increased kernel weight. The contribution of arbuscular mycorrhizal fungi (AMF) to the total phospholipid fatty acid increased in both treatments; however, the rate of this increase was greater in the weedy treatment than the less-weedy treatment (from 2.9 to 3.9%, from 2.8 to 3.1%, respectively). Weed dry biomass was positively correlated with AMF% in the less-weedy treatment only. Organic systems tend to be weedier than conventional systems. We found that weeds are important determinants of AMF proliferation in soil. In addition, choosing wheat cultivars that maintain important yield components under severe weed stress is one strategy to maximize yields in organic systems.


2004 ◽  
Vol 83 (2) ◽  
pp. 143-154 ◽  
Author(s):  
WEN ZENG ◽  
SUJIT GHOSH ◽  
BAILIAN LI

Diallel mating is a frequently used design for estimating the additive and dominance genetic (polygenic) effects involved in quantitative traits observed in the half- and full-sib progenies generated in plant breeding programmes. Gibbs sampling has been used for making statistical inferences for a mixed-inheritance model (MIM) that includes both major genes and polygenes. However, using this approach it has not been possible to incorporate the genetic properties of major genes with the additive and dominance polygenic effects in a diallel mating population. A parent block Gibbs sampling method was developed in this study to make statistical inferences about the major gene and polygenic effects on quantitative traits for progenies derived from a half-diallel mating design. Using simulated data sets with different major and polygenic effects, the proposed method accurately estimated the major and polygenic effects of quantitative traits, and possible genotypes of parents and progenies. The impact of specifying different prior distributions was examined and was found to have little effect on inference on the posterior distribution. This approach was applied to an experimental data set of Loblolly pine (Pinus taeda L.) derived from a 6-parent half-diallel mating. The result indicated that there might be a recessive major gene affecting height growth in this diallel population.


1983 ◽  
Vol 115 (6) ◽  
pp. 629-636 ◽  
Author(s):  
O. O. Olfert ◽  
M. K. Mukerji

AbstractStudies showed that the type of damage, the timing of damage with the phenological stage of the crop, and the amount of available soil moisture influenced the growth response of spring wheat to acute levels of grasshopper damage and acute levels of artificial damage. Ground-level cutting of plants resulted in the greatest reduction in plant biomass and crop yield, while grasshopper damage and artificial stripping of leaf material did not result in as severe a reduction in either biomass or yield.Damaged plants were not able to recover lost biomass when damage occurred any later than the early stages of tillering despite observed relative growth rates which were higher than control plants. The greatest degree of recovery occurred in study sites with the greatest amount of available soil moisture.The most detrimental effect of damage on yield was the reduction of heads per plant and kernel weight. In most cases differences in the number of seeds per head between damaged and control plants were not evident.


1969 ◽  
Vol 49 (5) ◽  
pp. 581-586 ◽  
Author(s):  
M. L. Kaufmann ◽  
V. M. Bendelow ◽  
R. J. Baker

Phenotypic correlations among five quality traits and five agronomic traits were calculated for three groups of 110 lines of a spring wheat cross (Triticum aestivum L.) grown in a total of four years in central Alberta. All correlations among pairs of traits were homogeneous from year to year with the exception of four involving maturity, yield, height and grain nitrogen content. The large negative correlation between nitrogen content and yield was judged detrimental to the prospects of simultaneous improvement of both traits. Maturity, height, kernel weight and yield were all positively interrelated. Large negative correlations were observed between sedimentation, value and tolerance index and between nitrogen content and starch damage. Sedimentation value and dough development time exhibited a strong positive relationship. The mean value for lines fell within the range of the parents in all cases except for sedimentation value and height.


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