scholarly journals Estimation of genetic erosion on Ethiopian tetraploid wheat landraces using different approaches

2021 ◽  
Vol 2 (4) ◽  
pp. 66-71
Author(s):  
Alemayehu Zemede Lemma ◽  
Firew Mekbib ◽  
Kebebew Assefa Abebe ◽  
Zewdie Bishaw

The demand and use of improved crop varieties by farmers has increased in the central highlands of Ethiopia, where continuous loss of local traditional varieties has been occurring in the last two to three decades. The objectives of the study were to assess the extent of genetic erosion and perception of farmers and associated causes for the reduction of traditional farmers' varieties. Direct field assessment covering 56 wheat farms and a survey in which 149 farmers participated were carried out in three districts of central Ethiopia. Based on data collected during direct farm assessment, the loss of genotypes was found to be 88% in Ada followed by 80% and 60% in Lume and Gimbichu districts, respectively. The farmer survey indicated an even greater loss of diversity of100% in Ada followed by Lume (93%) and Gimbichu (67%). Diseases and pests as well as shorter growing seasons associated with climate change were identified as main causes for farmers to switch to modern varieties. The expansion of high yielding improved bread and durum wheat varieties also contributed to gradually replace local durum wheat varieties by local farmers of these districts. Overall, genetic erosion of tetraploid wheat varied among the three districts of central Ethiopia. Reductions in the number of farmers and area coverage in the study districts could be used as good indicators for the existence of genetic erosion.

Author(s):  
Priscilla Glenn ◽  
Junli Zhang ◽  
Gina Brown-Guedira ◽  
Noah DeWitt ◽  
Jason P. Cook ◽  
...  

Abstract Key message We discovered a natural FT-A2 allele that increases grain number per spike in both pasta and bread wheat with limited effect on heading time. Abstract Increases in wheat grain yield are necessary to meet future global food demands. A previous study showed that loss-of-function mutations in FLOWERING LOCUS T2 (FT2) increase spikelet number per spike (SNS), an important grain yield component. However, these mutations were also associated with reduced fertility, offsetting the beneficial effect of the increases in SNS on grain number. Here, we report a natural mutation resulting in an aspartic acid to alanine change at position 10 (D10A) associated with significant increases in SNS and no negative effects on fertility. Using a high-density genetic map, we delimited the SNS candidate region to a 5.2-Mb region on chromosome 3AS including 28 genes. Among them, only FT-A2 showed a non-synonymous polymorphism (D10A) present in two different populations segregating for the SNS QTL on chromosome arm 3AS. These results, together with the known effect of the ft-A2 mutations on SNS, suggest that variation in FT-A2 is the most likely cause of the observed differences in SNS. We validated the positive effects of the A10 allele on SNS, grain number, and grain yield per spike in near-isogenic tetraploid wheat lines and in an hexaploid winter wheat population. The A10 allele is present at very low frequency in durum wheat and at much higher frequency in hexaploid wheat, particularly in winter and fall-planted spring varieties. These results suggest that the FT-A2 A10 allele may be particularly useful for improving grain yield in durum wheat and fall-planted common wheat varieties.


2021 ◽  
Vol 181 (4) ◽  
pp. 22-28
Author(s):  
Kh. N. Rustamov ◽  
Z. I. Akparov ◽  
M. A. Abbasov

Background. Studies into the adaptability of the genetic diversity of cultivated plants and their wild relatives to various environments are induced by global climate change. Introduction of adaptive wheat cultivars resistant to environmental stressors is the basis for stable harvests. This article presents the results of a research into the adaptive value of indigenous durum wheat varieties and improved cultivars released in different years in Azerbaijan.Materials and methods. The experiments were carried out in the foothills of Mountainous Shirvan under unsecured non-irrigation at Gobustan Experiment Station of the Research Institute of Crop Husbandry. In 2012–2014, contrasting in weather conditions, levels and structure of yield were analyzed. VIR’s guidelines were used to study 42 durum wheat varie ties, including 10 landraces. The years of study differed sharply in rainfall. Selyaninov’s hydrothermal coefficient was used to assess the conditions of growing seasons.Results. Mostly modern cultivars of the semi-intensive type were distinguished for a set of agrobiological traits. Adaptability coefficients (0.81–1.23) showed that the response of the studied varieties to unfavorable conditions was highly expressed. Indigenous landraces ‘Ag bughda’ and ‘Bozak’, old breeding varieties ‘Arandani’, ‘Ag bughda 13’, ‘Kahraba’ and ‘Mirbashir 50’, and new cultivars ‘Karagilchig 2’ and ‘Barakatli 95’ had the highest adaptability coefficients. The first of them demonstrated stable yield, and the latter two were also resistant to stressors.Conclusion. Durum wheat yields under the conditions of moderately continental climate in Mountainous Shirvan depended on the number and weight of grains per ear. The varieties identified for the best adaptability are recommended to be included in crosses to develop new plastic cultivars of durum wheat. 


2021 ◽  
Author(s):  
Angelo Sicilia ◽  
Umberto Anastasi ◽  
Michele Bizzini ◽  
Stefania Montemagno ◽  
Carmelo Nicotra ◽  
...  

Abstract Cereal landraces are a very valuable resource in contemporary agriculture. A renewed focus for breeding purposes could ameliorate some negative consequences of modern agriculture and conventional breeding, such as the loss of genetic diversity. A strategy combining molecular genotyping and characterization of morpho-agronomic traits related to productivity is proposed to assess a group of tetraploid wheat landraces named “Bufala”, historically cultivated in the mountain areas of Sicily and used for the production of a traditional bread type locally appreciated. A total of 55 SSR molecular markers were used to detect pattern of diversity for 30 rivet and durum wheat genotypes. Furthermore, phenotyping was than conducted for 8 morpho-agronomic traits. Discriminant analysis of principal components (DAPC), STRUCTURE and phylogenetical analysis allowed to identify three groups, two of them genetically close and including both “Bufala” and “Bufala-related” rivet landraces. To the third group old and more recent durum wheat varieties, constituting the outgroup, were assigned. Clustering was confirmed by Principal Component Analysis (PCA). Finally, a correlation analysis showed as “Bufala” genotypes are characterized by lower ear density compared with the other studied genotypes, a major ear length and a later earing time. The generated knowledge about the levels of diversity and population structure could be an important contribution for parent selection in tetraploid wheat breeding programs in order to define a plant ideotype suitable for low-input and organic cropping systems, as well as for germplasm conservation and management.


Plants ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 130
Author(s):  
Angelo Sicilia ◽  
Umberto Anastasi ◽  
Michele Bizzini ◽  
Stefania Montemagno ◽  
Carmelo Nicotra ◽  
...  

Cereal landraces are a very valuable resource in contemporary agriculture. A renewed focus for breeding purposes could ameliorate some negative consequences of modern agriculture and conventional breeding, such as the loss of genetic diversity. One strategy combining molecular genotyping and characterization of morpho-agronomic traits related to productivity is proposed to assess a group of tetraploid wheat landraces named Bufala, historically cultivated in the mountain areas of Sicily and characterized by adaptability in terms of cold tolerance, ability to grow in marginal soils, weed competitiveness and resistance to diseases. A total of 55 SSR molecular markers were used to detect patterns of diversity in 30 rivet and durum wheat genotypes. Furthermore, phenotyping was then conducted for 8 morpho-agronomic traits. Discriminant analysis of principal components (DAPC), STRUCTURE and phylogenetical analysis allowed to identify three groups, two of them genetically close and including both Bufala and Bufala-related rivet landraces. To the third group, old and more recent durum wheat varieties, constituting the outgroup, were assigned. Clustering was confirmed by Principal Component Analysis (PCA). Finally, a correlation analysis showed that Bufala genotypes are characterized by lower ear density, major ear length and later earing time compared with the other studied genotypes. The levels of diversity and population structure could be an important contribution to parent selection in tetraploid wheat breeding programs, as well as to germplasm conservation and management.


Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 788 ◽  
Author(s):  
Umberto Anastasi ◽  
Sebastiano Andrea Corinzia ◽  
Salvatore Luciano Cosentino ◽  
Danilo Scordia

Chemical input reduction in agricultural systems is strongly demanded with the aim to improve the quality and the safety of food/feed products in an environmental sustainable perspective. Durum wheat is the most important food crop widely grown across the Mediterranean basin. However, the choice of tailored-genotypes can represent a key strategy in resource limiting conditions. The present study investigated the performance of fourteen commercial durum wheat varieties, in terms of morphologic, productive and quality traits under two cropping systems, conventional (CH) and no-chemical input (NC), for two growing seasons. The NC cropping system affected plant phenology, grain yield, and its components (i.e., ears m−2 and test weight). However, the negative influence exerted by the NC depended by the growing season (significant interaction between growing season and cropping system), which in turn affected the production behavior of genotypes (significant interaction between growing season and genotype). The additive main effect and multiplicative interaction (AMMI) analysis showed that genotype (G) effect explained the 4.3% of the total variability, the environment (E) the 71.7% and the G × E interaction the 9.4%. The AMMI stability value (ASV) indicated that Meridiano, Claudio, Saragolla, and Normanno were the most stable genotypes among environments (combination of years and management systems). An integrated environmental assessment, including a soil nitrogen balance, can help to provide a more holistic approach to the sustainability of the no-chemical Mediterranean cropping systems based on cereal-legume rotation.


Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1691
Author(s):  
Giulia Cibecchini ◽  
Paola Cecere ◽  
Giorgio Tumino ◽  
Caterina Morcia ◽  
Roberta Ghizzoni ◽  
...  

The development of a colorimetric mono-varietal discriminating assay, aimed at improving traceability and quality control checks of durum wheat products, is described. A single nucleotide polymorphism (SNP) was identified as a reliable marker for wheat varietal discrimination, and a rapid test for easy and clear identification of specific wheat varieties was developed. Notably, an approach based on the loop-mediated isothermal amplification reaction (LAMP) as an SNP discrimination tool, in combination with naked-eye visualization of the results, was designed and optimized. Our assay was proven to be effective in the detection of adulterated food products, including both substitution and mixing with different crop varieties.


2021 ◽  
Author(s):  
Priscilla Glenn ◽  
Junli Zhang ◽  
Gina Brown-Guedira ◽  
Noah DeWitt ◽  
Jason P. Cook ◽  
...  

Abstract Increases in wheat grain yield are necessary to meet future global food demands. A previous study showed that loss-of-function mutations in FLOWERING LOCUS T2 ( FT2 ) increase spikelet number per spike (SNS), an important grain yield component. Unfortunately, associated reductions in fertility offset potential increases in grain number. Here, we report a natural mutation resulting in an aspartic acid to alanine change at position 10 (D10A) associated with significant increases in SNS and no negative effects on fertility. Using a high-density genetic map, we delimited the SNS candidate region to a 5.2 Mb region on chromosome 3AS including 28 genes. Among them, only FT-A2 showed a non-synonymous polymorphism (D10A) present in two different populations segregating for the SNS QTL on chromosome arm 3AS. These results, together with the known effect of the ft-A2 mutations on SNS, suggest that variation in FT-A2 is the most likely cause of the observed differences in SNS. We validated the positive effects of the A10 allele on SNS, grain number, and grain yield per spike in near-isogenic tetraploid wheat lines and in an hexaploid winter wheat population. The A10 allele is present at very low frequency in durum wheat and at much higher frequency in hexaploid wheat, particularly in winter and fall-planted spring varieties. These results suggest that the FT-A2 A10 allele may be particularly useful for improving grain yield in durum wheat and fall planted common wheat varieties.


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