Phenotypic diversity and relationships among a worldwide durum wheat (Triticum turgidum L. var. durum) germplasm collection under rainfed conditions of Iran

2013 ◽  
Vol 64 (2) ◽  
pp. 87 ◽  
Author(s):  
Reza Mohammadi ◽  
Ahmed Amri

Information on the variation available for different plant attributes has enabled germplasm collections to be effectively utilised in crop improvement. This study evaluated 380 durum wheat landraces, representing a worldwide durum wheat collection from 16 geographical origins, for several phenological and agronomic traits under rainfed conditions of Iran during three consecutive cropping seasons (2008–11). The experimental design was an unreplicated trial for all landraces, augmented by four repeated check cultivars. Best linear unbiased predictions (BLUPs) representing adjusted genotypic means were generated for individual trials using a mixed model. Multivariate analyses were used to measure the phenotypic diversity within the germplasm collection and relationships among landraces from different geographical regions. Combined analysis of variance indicated significant differences between years, landraces, and their interaction effects, indicating high variability among the germplasm across the years for each studied trait. Low heritability coupled with low genetic advance as a percentage of the mean was observed for days to heading (DTH) and days to maturity (DTM), whereas moderate heritability with moderate genetic advance as a percentage of the mean was exhibited for grain yield (YLD) followed by 1000-kernel weight (TKW) and plant height (PHT). According to Shannon’s phenotypic diversity index, collections from Iran (which represented a high percentage of germplasm tested) exhibited lower diversity in quantitative traits, especially for phenological traits, i.e. DTH and DTM, relative to landraces from other origins. Biplot analyses indicated several significant patterns among landraces from different geographical regions. The landraces with American and Australian origins were closely associated with each other and can be characterised by low yield productivity, high PHT, and high infestation by wheat stem sawfly (WSS). In contrast, the germplasm from Asian origins showed high yield potential and high TKW with good tolerance to WSS. The results indicated that the Iranian landraces with the lowest yield tend to be late in flowering and maturity. In conclusion, landraces with a wide genetic diversity were identified and can be used to achieve breakthrough in the durum wheat genetic improvement.

Agronomy ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 454 ◽  
Author(s):  
Alejandro del Pozo ◽  
Iván Matus ◽  
Kurt Ruf ◽  
Dalma Castillo ◽  
Ana María Méndez-Espinoza ◽  
...  

In Chile, durum wheat is cultivated in high-yielding Mediterranean environments, therefore breeding programs have selected cultivars with high yield potential in addition to grain quality. The genetic progress in grain yield (GY) between 1964 and 2010 was 72.8 kg ha−1 per year. GY showed a positive and significant correlation with days to heading, kernels per unit ground area and thousand kernel weight. The gluten and protein content tended to decrease with the year of cultivar release. The correlation between the δ13C of kernels and GY was negative and significant (−0.62, p < 0.05, for all cultivars; and −0.97, p < 0.001, excluding the two oldest cultivars). The yield progress (genetic plus agronomic improvements) of a set of 40–46 advanced lines evaluated between 2006 and 2015 was 569 kg ha−1 per year. Unlike other Mediterranean agro-environments, a longer growing cycle together with taller plants seems to be related to the increase in the GY of Chilean durum wheat during recent decades.


Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1992
Author(s):  
Hafid Aberkane ◽  
Ahmed Amri ◽  
Bouchra Belkadi ◽  
Abdelkarim Filali-Maltouf ◽  
Jan Valkoun ◽  
...  

Durum wheat (Triticum turgidum subsp. durum) is mostly grown in Mediterranean type environments, characterized by unpredictable rainfall amounts and distribution, heat stress, and prevalence of major diseases and pests, all to be exacerbated with climate change. Pre-breeding efforts transgressing adaptive genes from wild relatives need to be strengthened to overcome these abiotic and biotic challenges. In this study, we evaluated the yield stability of 67 lines issued from interspecific crosses of Cham5 and Haurani with Triticum dicoccoides, T. agilopoides, T. urartu, and Aegilops speltoides, grown under 15 contrasting rainfed and irrigated environments in Morocco, and heat-prone conditions in Sudan. Yield stability was assessed using parametric (univariate (e.g., Bi, S2di, Pi etc) and multivariate (ASV, SIPC)) and non-parametric (Si1, Si2, Si3 and Si6) approaches. The combined analysis of variance showed the highly significant effects of genotypes, environments, and genotype-by-environment interaction (GEI). The environments varied in yield (1370–6468 kg/ha), heritability (0.08–0.9), and in their contribution to the GEI. Several lines derived from the four wild parents combined productivity and stability, making them suitable for unpredictable climatic conditions. A significant advantage in yield and stability was observed in Haurani derivatives compared to their recurrent parent. Furthermore, no yield penalty was observed in many of Cham5 derivatives; they had improved yield under unfavorable environments while maintaining the high yield potential from the recurrent parent (e.g., 142,026 and 142,074). It was found that a limited number of backcrosses can produce high yielding/stable germplasm while increasing diversity in a breeding pipeline. Comparing different stability approaches showed that some of them can be used interchangeably; others can be complementary to combine broad adaption with higher yield.


2018 ◽  
Vol 46 (1) ◽  
pp. 190-196 ◽  
Author(s):  
Daniela MADRID ◽  
Eduardo SALGADO ◽  
Gabriela VERDUGO ◽  
Pablo OLGUÍN ◽  
Dimitrios BILALIS ◽  
...  

Coastal/lowland quinoa ecotype is an important source of germplasm due to its cultivation in cold-temperate and high latitude areas. However, the interaction of its morphological traits and yields to define breeding criteria is unknown. The present study was designed to characterize the phenotypic diversity of twelve coastal/lowland quinoas using sixteen standardized morphological descriptors under rainfed conditions in central Chile. Complementary analysis of uni- and multi- variate tools allowed a fuller understanding of interrelationships within quinoa germplasm. Through the analysis of frequency distribution, it was possible to determine that genotypes were characterized by plants having low height and medium grain yield. Cluster analysis revealed that plant morphological variables were independently grouped from grain yield components. Additionally, principal component analysis (PCA, 74.8% of total variation data), revealed the existence of three outstanding genotypes (QC01, QC02 and QC05) that were distantly located from the average dispersion of entire germplasm collection. These genotypes were associated with grain yield components, allowing the identification of two groups of high yield (VI and VII), which yielded 3337.7 and 3052.0 kg ha-1, respectively. The data set presented in this study is the first report of coastal/lowland quinoas assessed in central Chile and could assist the development of breeding programmes in cold-temperate areas having similar agro-climatic conditions.


2009 ◽  
Vol 7 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Yifru Teklu ◽  
Karl Hammer

In this paper, Shannon–Weaver diversity indices were employed to examine the phenotypic diversity in 271 Ethiopian tetraploid wheat accessions in relation to characters, regions of origin and altitude. Moreover, review of genetic diversity studies in Ethiopian tetraploid wheat was made to explore breeding opportunities. The diversity index varied widely across regions. Among the four altitudinal classes, the highest (0.72) and lowest (0.61) mean diversity indices were observed in altitude classes II and IV, respectively. The diversity index (H′) showed that most traits are polymorphic. The partitioning of the total phenotypic diversity into within- and among-region diversity indicated that 71% of the total variation was attributed to the within-region diversity. Principal component analysis was computed to examine the regional and altitudinal patterns of variation. On regional bases, the first four axes, whose eigenvalues are greater than 1, explained about 82% of the observed phenotypic diversity in the 271 tetraploid wheat accessions. On altitudinal bases, however, only the first two principal components explained 89.7% of the total variation. In general, phenotypic diversity showed considerable differences for each trait in different geographical regions and altitudinal classes which could be utilized in wheat improvement programmes. Breeding opportunities and strategies are suggested.


2001 ◽  
Vol 81 (1) ◽  
pp. 17-27 ◽  
Author(s):  
C. A. Grant ◽  
K. R. Brown ◽  
G. J. Racz ◽  
L. D. Bailey

Effective fertilizer management is critical to maintain economic production and protect long-term environmental quality. Field studies were conducted over 4 yr at two locations in southwestern Manitoba to determine the effect of source, timing and placement of N on grain yield and N recovery of durum wheat (Triticum durum L. ‘Sceptre’) under reduced-tillage (RT) and conventional-tillage (CT) management. The effect of N management on durum grain yield and N recovery differed with soil type and tillage system. On the clay loam (CL) soil, lower yields with fall- as compared with spring-banded N were more frequent under RT than CT. Lower yields occurred more frequently with fall-applied as compared with spring-applied urea ammonium nitrate (UAN) than when urea or NH3 was the N source. On the drier fine sandy loam (FSL) soil, fall applications of N generally produced similar to higher grain yield than did spring applications. Differences among fertilizer sources and tillage systems were much less frequent with spring than fall applications of N. Where differences occurred, durum grain yields were higher with in-soil than surface applications of urea or UAN. In-soil applications of urea and UAN increased durum grain yield as compared with surface applications more frequently under RT than CT on the CL soil where yield potential was high, whereas increases on the FSL were as common under CT as under RT. On soils with a high yield potential, enhanced immobilisation and/or volatilisation of surface-applied N may reduce grain yield by reducing available N, particularly under RT. Selection of a suitable source-timing and placement combination to optimise crop yield may be more important under RT than CT. Key words: Conservation tillage, direct seeding, placement


1999 ◽  
Vol 4 (2) ◽  
pp. 53
Author(s):  
R. Ahmad ◽  
A. Tanveer ◽  
J. C. Stark ◽  
T. Mustafa

Selection for drought tolerance typically involves evaluating genotypes for either high yield potential or stable performance under varying degrees of water stress. Field Studies were conducted in 1992 and 1993 to assess methods for evaluating genotypes with combined high yield potential and stability, in both years, 12 spring wheat (Triticum aestivum. L.) genotypes were grown under two irrigation levels (well-watered and stressed) imposed between tillering and anthesis with a line-source sprinkler irrigation system. Drought susceptibility index (the ratio of the yield of genotype in drought to the yield of the same genotype in well watered conditions standardized by the mean yield of all genotypes in drought and well watered conditions) and relative yield (yield of an individual genotype under drought divided by the yield of the highest yielding individual genotype in a population under drought) values were used to describe yield stability and yield potential of the 12 spring wheat genotypes. There were year-to-year variations in drought susceptibility index (DSI) and relative yield (RY) values within genotypes and changes in genotypic rankings within years. The DSI values ranged from 0.42 to 1.24 in 1992 and from 0.51 to 1.59 in 1993. The mean RY were 0.79 and 0.86 in 1992 and 1993, respectively. The DSI did not provide a good indication of yield potential as some genotypes has DSI < 1 but RY lower than average under water-stressed conditions. The RY (higher than average) under water stress was a good indicator of yield potential of a genotype per se but gave no indication of yield stability. The plots of DSI vs. RY values were found useful in identifying genotypes with high yield potential and relatively stable yield performance under different moisture regimes.


2011 ◽  
Vol 11 (3) ◽  
pp. 276-279 ◽  
Author(s):  
Joaquim Geraldo Cáprio da Costa ◽  
Leonardo Cunha Melo ◽  
Helton Santos Pereira ◽  
Maria José Del Peloso ◽  
Luís Cláudio de Faria ◽  
...  

BRS Esplendor is a common bean cultivar with black grain, suitable for 12 Brazilian states. The mean productivity is 2,156 kg ha-1, by 7.5 % higher than of controls, has a high yield potential (4,120 kg ha-1), upright growth, high tolerance to lodging and high resistance to anthracnose, fusarium wilt and common bacterial blight.


2021 ◽  
pp. 51-64
Author(s):  
Messaoudi Noura ◽  
Benderradji Laid ◽  
Bouzerzour Hammena ◽  
Benmahammed Ammar ◽  
Brini Faiçal

Knowledge of agro-physiological traits associated with drought tolerance would be useful for developing breeding materials for drought-prone environments. This study was conducted to estimate genetic variability among nine durum wheat genotypes in response to drought. Our results indicated that the effect of the campaign, genotype, and genotype × interaction was significant for the thirteen variables measured, except for the relative water content. The variability observed was greater for grain yield, biomass, ear fertility, straw and economic yields, chlorophyll content, and cell integrity. Heritability was high for the number of grains per ear and the chlorophyll content; medium for thousand kernel weights, low for grain yield, biomass, and economic yield, and zero for the rest of the variables measured. The results also showed that the agro-morphological characters were significantly linked to each other, unlike the physiological characters which showed non-significant relation between them and with the agro-morphological characters. This suggests that among the varieties evaluated, the selection of those which are tolerant and with high yield potential should therefore be made on a case-by-case basis and not based on a specific physiological character, a marker of tolerance, highly correlated with yield grain. The nine varieties evaluated were subdivided into three divergent clusters of three varieties each. Cluster C1 consists of the least performing varieties, unlike the other two clusters which bring appreciable gains for several characteristics including grain yield, biomass, the weight of 1000 grains, straw yield, and ear fertility and a marked improvement in chlorophyll content and a significant reduction in damage to the cell membrane by thermal stress. In conclusion and following their divergence, it is suggested to use the varieties of clusters C2 and C3 in crossing with the varieties of cluster C1 to improve and reconcile stress tolerance and yield potential in the same genetic background.


1987 ◽  
Vol 108 (2) ◽  
pp. 469-477 ◽  
Author(s):  
S. R. Waddington ◽  
M. Osmanzai ◽  
M. Yoshida ◽  
J. K. Ransom

SummaryTwo trials designed to measure progress in the yield of durum wheat cultivars released in Mexico by the Institute Nacional de Investigaciones Agrícolas over the period 1960–84 were grown in the Yaqui Valley, Sonora, Mexico, during the 1983–4 and 1984–5 cropping seasons. The trials compared grain yield, above-ground biomass, harvest index (ratio of dry grain yield to dry above-ground biomass), yield components, grain-growth rates and phenological characters for eight key cultivars and the modern advanced line, Carcomun ‘S’, when grown at a high level of agronomic inputs and management.The grain yield of durum wheat was estimated to have risen for 25 years of breeding from 3·70 to 8·40 t/ha. The estimated average annual rates of increase in grain yield for the periods 1960–71 and 1971–85 were 251 and 121 kg/ha respectively. Grain yield improvements were based on a linear increase in the number of grains/m2 over the 25-year period, the result of more grains per spikelet. An improved above-ground biomass at maturity was a feature of the two modern genotypes, Altar 84 and Carcomun ‘S’. Harvest index increased with each new cultivar up to the release of Mexicali 75 in 1975, but thereafter the higher grain yields achieved with the modern genotypes were not associated with a higher harvest index. Thousand-grain weight remained steady for the released cultivars but fell slightly for the advanced line Carcomun ‘S’. Improvements in yield were not associated with a longer cropping cycle.It is concluded that a breeding strategy combining selection for morphological characters thought to confer high yield potential, such as a more erect leaf posture and high number of grains per spikelet, with selection for grain yield per se has been successful in improving the grain yield of durum wheats adapted to north-west Mexico. Improvements have come not only in the size of the grain sink and the efficiency of assimilate partition to grain but also in the biomass produced above ground.


Agronomy ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 21 ◽  
Author(s):  
Norberto Guilengue ◽  
Sofia Alves ◽  
Pedro Talhinhas ◽  
João Neves-Martins

Lupinus mutabilis (tarwi) is a species of Andean origin with high protein and oil content and regarded as a potential crop in Europe. The success in the introduction of this crop depends in part on in depth knowledge of the intra-specific genetic variability of the collections, enabling the establishment of breeding and conservation programs. In this study, we used morphological traits, Inter-Simple Sequence Repeat markers and genome size to assess genetic and genomic diversity of 23 tarwi accessions under Mediterranean conditions. Phenotypic analyses and yield component studies point out accession LM268 as that achieving the highest seed production, producing large seeds and efficiently using primary branches as an important component of total yield, similar to the L. albus cultivars used as controls. By contrast, accession JKI-L295 presents high yield concentrated on the main stem, suggesting a semi-determinate development pattern. Genetic and genomic analyses revealed important levels of diversity, however not relatable to phenotypic diversity, reflecting the recent domestication of this crop. This is the first study of genome size diversity within L. mutabilis, revealing an average size of 2.05 pg/2C (2001 Mbp) with 9.2% variation (1897–2003 Mbp), prompting further studies for the exploitation of this diversity.


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