scholarly journals Wheat grain width: A clue for re-exploring visual indicators of grain weight

2021 ◽  
Author(s):  
Abbas Haghshenas ◽  
Yahya Emam ◽  
Saeid Jafarizadeh

Mean grain weight (MGW) is among the most frequently measured parameters in wheat breeding and physiology. Although in the recent decades, various wheat grain analyses (e.g. counting, and determining the size, color, or shape features) have been facilitated thanks to the automated image processing systems, MGW estimations has been limited to using few number of image-derived indices; i.e. mainly the linear or power models developed based on the projected area (Area). Following a preliminary observation which indicated the potential of grain width in improving the predictions, the present study was conducted to explore potentially more efficient indices for increasing the precision of image-based MGW estimations. For this purpose, an image archive of the grains was processed, which was harvested from a two-year field experiment carried out with 3 replicates under two irrigation conditions and included 15 cultivar mixture treatments (so the archive was consisted of 180 images taken from an overall number of more than 72000 grains). It was observed that among the more than 30 evaluated indices of grain size and shape, indicators of grain width (i.e. Minor & MinFeret) along with 8 other empirical indices had a higher correlation with MGW, compared with Area. The most precise MGW predictions were obtained using the Area*Circularity, Perimeter*Circularity, and Area/Perimeter indices. In general, two main common factors were detected in the structure of the major indices, i.e. either grain width or the Area/Perimeter ratio. Moreover, comparative efficiency of the superior indices almost remained stable across the 4 environmental conditions. Eventually, using the selected indices, ten simple linear models were developed and validated for MGW prediction, which indicated a relatively higher precision than the current Area-based models. The considerable effect of enhancing image resolution on the precision of the models has been also evidenced. It is expected that the findings of the present study improve the precision of the image-based MGW estimations, and consequently facilitate wheat breeding and physiological assessments.

2021 ◽  
Author(s):  
Abbas Haghshenas ◽  
Yahya Emam ◽  
Saeid Jafarizadeh

Abstract Background Mean grain weight (MGW) is among the most frequently measured parameters in wheat breeding and physiology. Although in the recent decades, various wheat grain analyses (e.g. counting, and determining the size, color, or shape features) have been facilitated thanks to the automated image processing systems, MGW estimations has been limited to using few number of image-derived indices; i.e. mainly the linear or power models developed based on the projected area (Area). Following a preliminary observation which indicated the potential of grain width in improving the predictions, the present study was conducted to explore potentially more efficient indices for increasing the precision of image-based MGW estimations. For this purpose, an image archive of the grains was processed, which was harvested from a two-year field experiment carried out with 3 replicates under two irrigation conditions and included 15 cultivar mixture treatments (so the archive was consisted of 180 images taken from an overall number of more than 72000 grains). Results It was observed that among the more than 30 evaluated indices of grain size and shape, indicators of grain width (i.e. Minor & MinFeret) along with 8 other empirical indices had a higher correlation with MGW, compared with Area. The most precise MGW predictions were obtained using the Area×Circularity, Perimeter×Circularity, and Area/Perimeter indices. In general, two main common factors were detected in the structure of the major indices, i.e. either grain width or the Area/Perimeter ratio. Moreover, comparative efficiency of the superior indices almost remained stable across the 4 environmental conditions. Eventually, using the selected indices, ten simple linear models were developed and validated for MGW prediction, which indicated a relatively higher precision than the current Area-based models. The considerable effect of enhancing image resolution on the precision of the models has been also evidenced. Conclusions It is expected that the findings of the present study, along with the simple predictive linear models developed and validated using the new image-derived indices, could improve the precision of the image-based MGW estimations, and consequently facilitate wheat breeding and physiological assessments.


1985 ◽  
Vol 57 (1) ◽  
pp. 1-66
Author(s):  
Reijo Karjalainen

Host-pathogen interaction between spring wheat and Septoria nodorum Berk. with applications for wheat breeding were studied. Ultrastructure of interactions was studied using electron microscopic techniques. Following inoculation, conidia of S. nodorum germinate, form appressoria anda penetration peg which directly penetrates through the cell walls. It is suggested that most penetration attempts fail because of cellular defence reactions, formation of papillae and cell wall alterations. Inoculation with low spore concentration reduced grain yield of Hankkija’s Taava cultivar by 10 % and 1000-grain weight by 14 %. Inoculation with high spore concentration on large plots of Tähti cultivar reduced grain yield by 32 % and 1000-grain weight by 18 %. Inoculation with high spore concentration on normal breeding plots of Tähti cultivar reduced grain yield by 35 % and 1000-grain weight by 21 % and the grain yield of Kadett cultivar by 27 % and 1000-grain weight by 20 %. Inheritance studies on F2 progenies of spring wheat crosses involving susceptible and moderately or highly resistant parents suggest that heredity component of symptom expression is moderate level and breeding success depends mainly on efficient screening techniques. Resistance was associated with tallness in crosses, and cultivar trials suggest that resistance is positively associated with late maturation time. Field screening techniques based on small plots and artificial inoculation showed that the most resistant entries were wild Triticum species and late and tall cultivars. Seedling plant tests based on attached seedling leaves and detached leaves revealed easily the most resistant and most susceptible cultivars. The overall correlation between seedling tests and field tests was quite high. The results are discussed in relation to wheat breeding strategies for resistance to S. nodorum.


2021 ◽  
Author(s):  
Pao Xue ◽  
Yu-yu Chen ◽  
Xiao-xia Wen ◽  
Bei-fang Wang ◽  
Qin-qin Yang ◽  
...  

Abstract Grain size is a key constituent of grain weight and appearance in rice. However, insufficient attention has been paid to the small-effect QTLs on grain size. In the present study, residual heterozygous populations were developed for mapping two genetically linked small-effect QTLs for grain size. After genotyping and phenotyping of five successive generations, qGS7.1 was dissected into three QTLs and two were selected for further analysis. qTGW7.2a was finally mapped into a 21.10-kb interval containing four annotated candidate genes. Transcript levels assay showed that the expression of candidates LOC_Os07g39490 and LOC_Os07g39500 were significantly reduced in the NIL- qTGW7.2a BG1 . Cytological observation indicated that qTGW7.2a regulated grain width through controlling cell expansion. Use the same strategy, qTGW7.2b was fine mapped into a 52.71-kb interval, showing a significant effect on grain length and width with opposite allelic directions but little on grain weight. Our study provides new genetic resources for yield improvement and fine-tunes of grain size in rice.


2013 ◽  
Vol 152 (6) ◽  
pp. 873-884 ◽  
Author(s):  
R. MOHAMMADI

SUMMARYRainfall and temperature are unpredictable in Mediterranean environments, which results in inconsistent environmental conditions for crop growth and a critical source of uncertainty for farmers and growers. The objectives of the present study were to: (i) quantify and compare the plasticity of durum breeding lines, a modern cultivar and landraces on the basis of yield and agronomic traits and (ii) study associations between plasticity of yield and plasticity of agronomic and phenological traits. Plasticity was quantified using linear models for 11 durum breeding lines, one modern cultivar and two landraces grown in 21 diversified environments. The results showed that the effects due to environment, genotype and genotype×environment (G×E) interaction were significant, which indicates the existence of differences among genotypes for plasticity. Yield ranged from 1939 to 2419 kg/ha across environments and the range of plasticity was 0·66–1·13. The breeding lines and the modern cultivar had higher grain yields compared with the landraces at the same level of plasticity. The landraces with below-average plasticity in yield were characterized as tall in stature and late in heading and maturity, whereas the breeding lines and modern cultivar with above-average plasticity in yield were early in heading and maturity, semi-dwarf and high-yielding, which indicates the success in breeding the materials for unpredictable environmental conditions. In conclusion, yield plasticity was associated with yield improvement and high yield plasticity tends to associate with earliness, shorter plants and low grain weight.


2016 ◽  
Vol 16 (1) ◽  
pp. 74-81 ◽  
Author(s):  
Hongchun Xiong ◽  
Huijun Guo ◽  
Yongdun Xie ◽  
Linshu Zhao ◽  
Jiayu Gu ◽  
...  

AbstractThe dwarfing wheat (Triticum aestivum L.) breeding has promoted a dramatic increase in yields. Since the utilized dwarfing genes in wheat are very limited, identification of novel dwarfing genes is necessary for improving the genetic diversity of wheat. In this study, more than 300 dwarfing wheat lines from induced mutation were screened by kompetitive allele-specific PCR and gibberellin (GA) treatment. The 17.49% of Rht-D1b and 1.37% of Rht-B1b dwarfing mutants were identified in this mutant group. Additionally, Rht-D1b mutants showed more effective in reduction of plant height and higher 1000-grain weight comparing with that of Rht-B1b mutants. By combing with comparison of yield components and expression profile of GA biosynthetic genes with wild-type, the GA-responsive mutant dm15 without directly involvement in GA metabolism, significantly increased 1000-grain weight but no change of other yield components in two locations of field experiments. Meanwhile, another elite mutant dm11 with change of GA biosynthetic genes expression was also identified. These mutants will be promising candidates for dwarfing wheat breeding.


Author(s):  
G. A. Batalova ◽  
I. G. Loskutov ◽  
S. N. Shevchenko ◽  
O. A. Zhuikova ◽  
N. V. Krotova ◽  
...  

The aim of the research was to develop a cultivar of naked oat with improved traits of productivity and grain quality for cultivation under climate change conditions and utilization in breeding practice as a source of useful economic properties. The pre-flag leaf’s area was found to render a considerable effect on the formation of the number of grains and grain weight in the panicle and on the total biomass (r= 0.78-0.85), while the area of leaves depended on the duration of the period from seedling emergence to wax ripeness (r = ‒0.79) and on agroclimatic conditions during the growing season (HTC, r = 0.76).  The flag leaf’s pigments (Chl a, Chl b, Car) were observed to have a sizable effect on the weight of 1000 grains during the period from flowering to milk ripeness (r = 0.79-0.88). The new naked cultivar ‘Virovets’ (1h07) with improved levels of productivity and grain quality (1000 grain weight: 29.2 g; crude protein content: up to 19.8%; oil of the oleic-linoleic group: 7.71%, grain volume weight: 670 g/l; pubescence: weak) was developed to be cultivated for food and feed purposes and be used in naked oat breeding as a source of high grain quality.


2019 ◽  
Author(s):  
Jian Yang ◽  
Yanjie Zhou ◽  
Yu'e Zhang ◽  
Weiguo Hu ◽  
Qiuhong Wu ◽  
...  

Abstract Background: Grain weight is an important yield component. Selection of advanced lines with heavy grains show high grain sink potentials and strong sink activity, which is an increasingly important objective in wheat breeding programs. Rice OsGS3 has been identified as a major quantitative trait locus for both grain weight and grain size. However, allelic variation of GS3 has not been characterized previously in hexaploid wheat. Results : We cloned 2445, 2393, and 2409 bp sequences of the homologs TaGS3-4A , TaGS3-7A , and TaGS3-7D in wheat ‘Changzhi 6406’, a cultivar that shows high grain weight. The TaGS3 genes each contained five exons and four introns, and encoded a deduced protein of 170, 169, and 169 amino acids, respectively. Phylogenetic analysis of plant GS3 protein sequences revealed GS3 to be a monocotyledon-specific gene and the GS3 proteins were resolved into three classes. The length of the atypical Gγ domain and the cysteine-rich region was conserved within each class and not conserved between classes. A single-nucleotide polymorphism in the fifth exon (at position 1907) of TaGS3-7A leads to an amino acid change (ALA/THR) and showed different frequencies in two pools of Chinese wheat accessions representing extremes in grain weight. Association analysis indicated that the TaGS3-7A-A allele was associated with higher grain weight in the natural population. The TaGS3-7A-A allele was favoured in global modern wheat cultivars but the allelic frequency varied among different wheat-production regions of China, which indicated that this allele is of potential utility to improve wheat grain weight in certain wheat-production areas of China. Conclusions : The novel molecular information on wheat GS3 homologs and the KASP functional marker designed in this study may be useful in marker-assisted breeding for genetic improvement of wheat.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yongzhen Wu ◽  
Jiahui Liu ◽  
Guimei Hu ◽  
Huixian Xue ◽  
Huiyuan Xu ◽  
...  

Flowering is central to the transformation of plants from vegetative growth to reproductive growth. The circadian clock system enables plants to sense the changes in the external environment and to modify the growth and development process at an appropriate time. Photoperiod-1 (Ppd-1), which is controlled by the output signal of the circadian clock, has played an important role in the wheat “Green Revolution.” In the current study, we systematically studied the relationship between Ppd-1 haplotypes and both wheat yield- and quality-related traits, using genome-wide association analysis and transgenic strategies, and found that highly appropriate haplotypes had been selected in the wheat breeding programs. Genome-wide association analysis showed that Ppd-1 is associated with significant differences in yield-related traits in wheat, including spike length (SL), heading date (HD), plant height (PH), and thousand-grain weight (TGW). Ppd-1-Hapl-A1 showed increased SL by 4.72–5.93%, whereas Ppd-1-Hapl-B1 and Ppd-1-Hapl-D1 displayed earlier HD by 0.58–0.75 and 1.24–2.93%, respectively, decreased PH by 5.64–13.08 and 13.62–27.30%, respectively, and increased TGW by 4.89–10.94 and 11.12–21.45%, respectively. Furthermore, the constitutive expression of the Ppd-D1 gene in rice significantly delayed heading date and resulted in reduced plant height, thousand-grain weight, grain width (GW), and total protein content. With reference to 40years of data from Chinese wheat breeding, it was found that the appropriate haplotypes Ppd-1-Hapl-A1, Ppd-1-Hapl-B1, and Ppd-1-Hapl-D1 had all been subjected to directional selection, and that their distribution frequencies had increased from 26.09, 60.00, and 52.00% in landraces to 42.55, 93.62, and 96.23% in wheat cultivars developed in the 2010s. A Ppd-B1 methylation molecular marker was also developed to assist molecular wheat breeding. This research is of significance for fully exploring the function of the Ppd-1 gene and its genetic resource diversity, to effectively use the most appropriate haplotypes and to improve crop yield and sustainability.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 816
Author(s):  
Ana B. Huertas-García ◽  
Laura Castellano ◽  
Carlos Guzmán ◽  
Juan B. Alvarez

Wild einkorn (Triticum monococcum L. ssp. aegilopoides (Link) Thell.) is a diploid wheat species from the Near East that has been classified as an ancestor of the first cultivated wheat (einkorn; T. monococcum L. ssp. monococcum). Its genome (Am), although it is not the donor of the A genome in polyploid wheat, shows high similarity to the Au genome. An important characteristic for wheat improvement is grain quality, which is associated with three components of the wheat grain: endosperm storage proteins (gluten properties), starch synthases (starch characteristics) and puroindolines (grain hardness). In the current study, these grain quality traits were studied in one collection of wild einkorn with the objective of evaluating its variability with respect to these three traits. The combined use of protein and DNA analyses allows detecting numerous variants for each one of the following genes: six for Ax, seven for Ay, eight for Wx, four for Gsp-1, two for Pina and three for Pinb. The high variability presence in this species suggests its potential as a source of novel alleles that could be used in modern wheat breeding.


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