scholarly journals Multivariate statistical analysis of some traits of bread wheat for breeding under rainfed conditions

2014 ◽  
Vol 59 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Mohsen Janmohammadi ◽  
Zahra Movahedi ◽  
Naser Sabaghnia

In order to evaluate several agro-morphological traits in 56 wheat genotypes, an experiment based on randomized complete block design with three replications was carried out. Principal component analysis (PCA) and factor analysis were used for understanding the data structure and trait relations. The PCA showed that five components explained 69% of the total variation among traits. The first PCA was assigned 28% and the second PCA was assigned 13% of total variation among traits. The first PCA was more related to grain number, floret number, tiller number, stem diameter, leaf width and spikelet number. Therefore, the selection may be done according to the first component and it was helpful for a good breeding program for development of high yielding cultivars. The correlation coefficient between any two traits is approximated by the cosine of the angle between their vectors in the plot of the first two PCAs and the most prominent relations were between grain diameter and grain yield; and between grain length and 1,000 seed weight. The factor analysis divided the eighteen traits into five factors and the first factor included stem diameter, leaf width, tiller number, spike length, floret number, spikelet number, grain number and grain yield. The second factor was composed of some morphological traits and indicated the importance of the grain diameter, grain length, 1,000 seed weight and grain yield. The two PCA and factor analysis methods were found to give complementary information, and therefore such knowledge would assist the plant breeders in making their selection. In other words, this data reduction would let the plant breeder reduce field costs required to obtain the genetic parameter estimates necessary to construct selection indices.

2014 ◽  
Vol 69 (1) ◽  
pp. 44-54
Author(s):  
NASER SABAGHNIA ◽  
MOHSEN JANMOHAMMADI ◽  
ADEL BASHIRI ◽  
REZA ASGHARI-SHIRGHAN

The genetic diversity among 56 bread wheat (Triticum aestivum L.) genotypes was evaluated by 18 agronomical traits in the experimental field at Maragheh, Iran. Significant differences among bread wheat genotypes in all of the measured traits i.e. stem diameter, plant height, leaf number, leaf length, leaf width, tiller number, internode length, peduncle length, spike length, floret number, spikelet number, grain number, length of awn, grain diameter, grain length, the number of days to flowering, thousand seed weight and grain yield. The coefficient of variation (CV) was high for grain yield (25.61%), number of tillers per plant (22.06%) and number of grains per spike (21.45). The other remaining traits recorded moderate to low CV estimates from 14.30% in grain number per spike to 4.81% in days to flowering. The largest thousand seed weight was 45.93 g, the lowest thousand seed weight was 26.16 g and the mean thousand seed weight was 37.85 g. The mean performance of grain yield was 5031.2 kg ha-1, the minimum grain yield was 2835.0 kg ha-1 and the maximum grain yield was 7125.3 kg ha-1. Ward’s minimum variance cluster analysis based on squared Euclidian distance on the raw data of 18 agronomic traits clearly separated five clusters. In general, cluster analysis of the 56 genotypes based on the selected agronomic traits was consistent with known information. Our plant materials could be important germplasm resources for enriching the genetic background of commercial cultivars. Such genetic differences of bread wheat traits studied in this investigation can be applied as a new source of variation in other breeding programs and crossing nurseries in breeding program


1995 ◽  
Vol 46 (3) ◽  
pp. 507 ◽  
Author(s):  
JA Palta ◽  
IRP Fillery

The effect of fertilizer N on the growth, post-anthesis water deficits and remobilization of dry matter in spring wheat was measured on a duplex soil at East Beverley, Western Australia. Nitrogen was applied at 15, 30 and 60 kg N ha-1 with half being applied at seeding and the remainder at 35 days after sowing (DAS), immediately before the onset of tillering. The applied N generated differences in early growth (76-117 g m-2) and dry matter at anthesis (410-693 g m-2), mainly through the effect of N on tiller number (120-171 m-2) and tiller size. It also generated differences in the water deficit, particularly after flowering. During the first 21 days after anthesis, midday flag leaf water potential fell at rates of 0.04, 0.07 and 0.13 MPa day-1 at 15, 30 and 60 kg N ha-1 respectively. Grain yield at 60 kg N ha-1 was increased by 20% relative to that of 15 kg N ha-1. The increase in grain yield resulted from an increase in the number of ears and grain number per ear. The high N treatment probably induced the increase in the number of fertile tillers (tillers with an ear), but reduced the grain size by 16% relative to the low N treatment. Contribution of preanthesis dry matter to grain yield was 193 g m-2 for the wheat receiving 60 kg N ha-1, 71 g m-2 for wheat which received 30 kg N ha-1 and only 16 g m-2 for wheat which received 15 kg N ha-1. This indicates that at high N supply, grain growth was substantially supported by pre-anthesis stored assimilates.


Author(s):  
Mohsen Janmohammadi ◽  
Naser Sabaghnia ◽  
Mojtaba Nouraein

Development of new bread wheat cultivars needs efficient tools to monitor trait association in a breeding program. This investigation was aimed to characterize grain yield components and some agronomic traits related to bread wheat grain yield. The efficiency of a breeding program depends mainly on the direction of the correlation between different traits and the relative importance of each component involved in contributing to grain yield. Correlation and path analysis were carried out in 56 bread wheat genotypes grown under field conditions of Maragheh, Iran. Observations were recorded on 18 wheat traits and correlation coefficient analysis revealed grain yield was positively correlated with stem diameter, spike length, floret number, spikelet number, grain diameter, grain length and 1000 seed weight traits. According to the variance inflation factor (VIF) and tolerance as multicollinearity statistics, there are inconsistent relationships among the variables and all traits could be considered as first-order variables (Model I) with grain yield as the response variable due to low multicollinearity of all measured traits. In the path coefficient analysis, grain yield represented the dependent variable and the spikelet number and 1000 seed weight traits were the independent ones. Our results indicated that the number of spikelets per spikes and leaf width and 1000 seed weight traits followed by the grain length, grain diameter and grain number per spike were the traits related to higher grain yield. The above mentioned traits along with their indirect causal factors should be considered simultaneously as an effective selection criteria evolving high yielding genotype because of their direct positive contribution to grain yield.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Fu Quan Yao ◽  
Xiao Hui Li ◽  
He Wang ◽  
Yu Ning Song ◽  
Zhong Qing Li ◽  
...  

Abstract Background Tiller number is a factor determining panicle number and grain yield in wheat (Triticum aestivum). Auxin plays an important role in the regulation of branch production. PIN-FORMED 1 (PIN1), an auxin efflux carrier, plays a role in the regulation of tiller number in rice (Oryza sativa); however, little is known on the roles of PIN1 in wheat. Results Nine homologs of TaPIN1 genes were identified in wheat, of which TaPIN1-6 genes showed higher expression in the stem apex and young leaf in wheat, and the TaPIN1-6a protein was localized in the plasma membrane. The down-expression of TaPIN1s increased the tiller number in TaPIN1-RNA interference (TaPIN1-RNAi) transgenic wheat plants, indicating that auxin might mediate the axillary bud production. By contrast, the spikelet number, grain number per panicle, and the 1000-grain weight were decreased in the TaPIN1-RNAi transgenic wheat plants compared with those in the wild type. In summary, a reduction of TaPIN1s expression increased the tiller number and grain yield per plant of wheat. Conclusions Phylogenetic analysis and protein structure of nine TaPIN1 proteins were analyzed, and subcellular localization of TaPIN1-6a was located in the plasma membrane. Knock-down expression of TaPIN1 genes increased the tiller number of transgenic wheat lines. Our study suggests that TaPIN1s is required for the regulation of grain yield in wheat.


2018 ◽  
Vol 77 ◽  
pp. 69-77
Author(s):  
Asadollah Ahmadikhah

Estimation of selection effects on changes of a trait is of vital importance for the success of any plantbreeding program, and helps to select the desirable breeding method. Heritability and genetic advance areimportant selection parameters, and selection success is a reflectance of selection response. To estimate selectioneffects on rice genetic parameters, a research was conducted using 4 different generations (two parents:Neda and Sadri, and two segregating populations: BC1F1 and BC1S1). After development of a backcross population,a single plant (BC1#4) was selected based on its desirable performance, particularly in heading date andseven other morphological traits. BC1F1 population compared to mid-parent performance showed advance forheading date, plant height, tiller number, hundred seed weight, weight of filled seeds per panicle and grainyield per plant, while mean performance of BC1F1 population compared to BC1S1 population showed advanceonly for heading date, plant height, tiller number and grain yield. Prevalence of additive genetic effects incontrolling panicle weight, hundred seed weight, weight of filled seeds per panicle, plant height and headingdate was observed, and in contrast prevalence of non-additive effects in controlling grain yield was observed.High general heritability was observed for most traits, while only heading date and plant height showeda considerable specific heritability (60.7% and 67.5%, respectively), and grain yield showed a relatively lowspecific heritability (37.0%). High expected genetic advance (ΔGe) was obtained for tiller number (49.4%),followed by grain yield (43.5%) and plant height (35.5%), while the highest real genetic advance (ΔGe) wasobtained for heading date (-8.5%) and tiller number (5.4%). High selection success was obtained only forheading date (51.8%). Altogether, the obtained results gave promise for selecting progenies with early maturityand semi-dwarfism in early segregating generations, while they suggested preference of heterosis for improvementof grain yield.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Ke Chen ◽  
Tao Guo ◽  
Xin-Min Li ◽  
Yi-Bing Yang ◽  
Nai-Qian Dong ◽  
...  

Abstract Background Leaf morphology and spikelet number are two important traits associated with grain yield. To understand how genes coordinating with sink and sources of cereal crops is important for grain yield improvement guidance. Although many researches focus on leaf morphology or grain number in rice, the regulating molecular mechanisms are still unclear. Results In this study, we identified a prohibitin complex 2α subunit, NAL8, that contributes to multiple developmental process and is required for normal leaf width and spikelet number at the reproductive stage in rice. These results were consistent with the ubiquitous expression pattern of NAL8 gene. We used genetic complementation, CRISPR/Cas9 gene editing system, RNAi gene silenced system and overexpressing system to generate transgenic plants for confirming the fuctions of NAL8. Mutation of NAL8 causes a reduction in the number of plastoglobules and shrunken thylakoids in chloroplasts, resulting in reduced cell division. In addition, the auxin levels in nal8 mutants are higher than in TQ, while the cytokinin levels are lower than in TQ. Moreover, RNA-sequencing and proteomics analysis shows that NAL8 is involved in multiple hormone signaling pathways as well as photosynthesis in chloroplasts and respiration in mitochondria. Conclusions Our findings provide new insights into the way that NAL8 functions as a molecular chaperone in regulating plant leaf morphology and spikelet number through its effects on mitochondria and chloroplasts associated with cell division.


1970 ◽  
Vol 23 (1) ◽  
pp. 1 ◽  
Author(s):  
HM Rawson

For 12 cultivars of wheat grown under a 21�C day/16�C night temperature regime, spikelet number was closely related to grain number, but not to grain yield per ear as individual grain weights differed considerably between cultivars. However, when spikelet number was varied by day length or vernalization treatment, grain yield per ear was clearly dependent on spikelet number within each cultivar.


2009 ◽  
Vol 23 (1) ◽  
pp. 40-48 ◽  
Author(s):  
Blakely H. Paynter ◽  
Andrea L. Hills

Western Australian growers are adopting no-tillage farming systems, which have a greater reliance on integrated weed management systems that include competitive cultivars, high seeding rates, strategic fertilizer placement, and narrow row spacing. At the same time, they are sowing more of their barley area to cultivars with a semidwarf habit. This study compared six two-row, spring malting barley cultivars with different morphological traits at two dates of planting and three crop densities, with nil-added and added rigid ryegrass at five sites. Four cultivars, ‘Buloke’, ‘Flagship’, ‘Hamelin’, and ‘Vlamingh’, had an erect early growth habit; the other two, ‘Baudin’ and ‘Gairdner’, had a prostrate, semidwarf early growth habit. Increasing the density of rigid ryegrass plants from 16 to 125 plants/m2decreased barley grain yield by reducing crop biomass production, tiller number, grain number, and harvest index. Average grain weight was also reduced at most sites. The impact of competition on grain yield varied across sites and cultivars, but did not interact with date of planting. Baudin, Flagship, and Hamelin were more competitive with rigid ryegrass than Buloke, Gairdner, and Vlamingh. Differences in competitiveness between cultivars did not appear to be strongly related to morphological traits that affect light interception such as canopy closure, plant height, and tiller number. Differences in cultivar competitiveness were cultivar-specific and not generic. Rigid ryegrass productivity (dry matter and tiller number) tended to be lower under the more competitive cultivars. Increasing barley plant density increased grain yield, and reduced both rigid ryegrass dry matter and tiller number. Barley density had a larger impact on rigid ryegrass productivity than crop cultivar. The impact of barley density on reducing rigid ryegrass tiller number was larger with the first planting date than the second, and higher in the added rigid ryegrass plots than the nil-added plots. This study highlights the importance of high barley seeding rate for the integrated management of rigid ryegrass.


2015 ◽  
Vol 66 (10) ◽  
pp. 1024 ◽  
Author(s):  
Haipei Liu ◽  
Iain R. Searle ◽  
Diane E. Mather ◽  
Amanda J. Able ◽  
Jason A. Able

Durum wheat production in southern Australia is limited when water deficit occurs immediately before and during anthesis. This study was conducted to determine the effect of genotypic variation on various yield, morphological and physiological responses to pre-anthesis water-deficit stress by evaluating 20 durum wheat (Triticum turgidum L. ssp. durum) genotypes over 2 years of glasshouse experiments. Grain number was the major yield component that affected yield under pre-anthesis water-deficit stress. Genotypes with less yield reduction also had less reduction in chlorophyll content, relative water content and leaf water potential, suggesting that durum genotypes tolerant of water-deficit stress maintain a higher photosynthetic rate and leaf water status. Weak to moderate positive correlations of morphological traits, including plant height and fertile tiller number, with grain number and biomass make the evaluation of high-yielding genotypes in rainfed conditions possible. Morphological traits (such as plant height and tiller number) and physiological traits (such as chlorophyll content, relative water content and leaf water potential) could therefore be considered potential indicators for indirect selection of durum wheat with water-deficit stress tolerance under Mediterranean conditions.


2014 ◽  
Vol 2 (2) ◽  
pp. 93-100
Author(s):  
Shahnaj Yesmina ◽  
Moushumi Akhtarb ◽  
Belal Hossain

The experiment was conducted to find out the effect of variety, nitrogen level and harvesting time on yield and seed quality of barley. The treatments used in the experiment consisted of two varieties viz. BARI Barley 4 and BARI Barley 5, three harvesting time viz. 35, 40 and 45 Days after Anthesis (DAA) and nitrogen levels viz. 0, 70, 85 and 100 kg N ha-1 . The experiment was laid out in a spilt- spilt-plot design with three replications assigning the variety to the main plot, harvesting time to the sub-plots and nitrogen level to the sub-sub plots. Variety had significant effects on the all yield attributes except fertile seeds spike-1 . Seed quality parameters viz. normal seeds spike-1 , deformed seeds spike-1 , germination (%) and vigour index were statistically significant. The variety BARI Barley 5 produced higher grain yield and seed quality than BARI Barley 4. Grain yield from BARI Barley 5 and BARI Barley 4 were 4.59 t ha-1 and 4.24 t ha-1 , respectively. Significantly, the highest 1000-seed weight (46.90 g) was produced by BARI Barley 5 than (37.90 g) BARI Barley 4. The result revealed that harvesting time had significant effect on yield and yield attributes and seed quality parameters. Seed yield was highest (4.65 t ha-1 ) when the crop harvested at 40 DAA and it was increased linearly from 35 DAA. Maximum quality seed and 1000-seed weight (43.20 g) was obtained when the crop harvested at 40 DAA. All the yields, yield attributes and seed quality parameters were significantly influenced by nitrogen levels. The highest grain yield (5.14 t ha-1 ) was obtained when BARI Barley 5 variety was fertilized by 100 kg N ha-1 and the lowest (3.14 t ha-1 ) was obtained from control treatments. Normal seeds spike-1 , vigour index, germination (%) were better at 85 kg N ha-1 in variety of BARI Barley 5 than BARI Barley 4. So it can be concluded that BARI Barley 5 showed better result when fertilized with 100 kg N ha-1 and harvested at 40 DAA for getting maximum yield and 85 kg N ha-1 and harvested at 40 DAA for getting better quality seed.


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