Genetic diversity of Cameroonian bread wheat (Triticum aestivum L.) cultivars revealed by microsatellite markers

Abstract

The assessment of genetic diversity is a key prerequisite for studying the adaptation of populations to new environmental conditions, and therefore for the selection of new varieties. The present investigation aimed to estimate the levels and genetic structure within bread wheat varieties grown in Cameroon. Thus, genetic diversity was assessed in 17 hexaploid wheat cultivars, using 11 microsatellite markers. Genetic resources were collected in the Northwest, Adamawa and North Regions. All pairs of specific marker loci used gave amplifications with allelic variations of size on all DNA of wheat accessions. A total of 77 alleles were detected among cultivars and the number of alleles per locus ranged from 2 to 13 with an average of 7, comparable to those observed in most previous studies. Gene diversity ranged from 0.46 (Xgdm 125) to 0.90 (Xgwm 177) with an average of 0.88, increasing with the number of alleles, with a correlation coefficient of 0.88 (Adamawa) and 0.76 (Northwest). Microsatellite markers used had an average value of polymorphic information content (PIC) of 0.69, indicating that these markers are highly informative in this study. These markers are valid and will make a contribution to the studies in hexaploid wheat. Moreover, cluster analysis at a genetic similarity of 80% and the principal component analysis, where the first two components explaining 59.86% of variation which structured 17 accessions in 5 main distinct groups. This high diversity revealed among wheat accessions, grown in Cameroon could be used in the breeding programs.

Population structure of Chinese southwest wheat germplasms resistant to stripe rust and powdery mildew using the DArT-seq technique

“…A PIC value higher than 0.5 is considered to be a sign of a very informative marker, while 0.5> PIC> 0.25 corresponded to an informative marker (BOTSTEIN et al, 1980). In the present study, the mean PIC value for both types marker was higher than 0.25, comparable to those observed in the study with same type marker (LOPES et al, 2015;SOHAIL et al, 2015), but lower than SSR marker (RAFEIPOUR et al, 2016;HONORE et al, 2017). PIC value is calculated as a maximum of 0.5 when a marker is scored as 50% of 0 and 50% of 1.…”

Genetic variation of bread wheat accessions in response to the cereal cyst nematode, Heterodera filipjevi

“…In previous studies, Landjeva et al (2006), reported the PIC values in Bulgarian winter wheat ranged from 0.10 to 0.81, which is confirmed by our study. Salem et al (2014) evaluated 33 diverse bread wheat varieties with Egyptian origin, using 17 SSR markers and the highest and lowest PIC value were 0.75 and 0.59, respectively. Erum et al (2013) reported the average values of 'h' and 'I' as 0.11 and 0.23, respectively.…”

“…The development of such varieties requires a continuous supply of a source of desirable genes and/or gene complexes. The sources of such genes could be: i) bread wheat varieties, which have not been used very intensively but have a higher general adaptation; ii) landraces; iii) wild relatives; and iv) weed species (Salem & Mattar, 2014).…”

“…In this regard, SSRs, due to their multi-allelic nature, have been extensively used in several crops (Hou et al, 2017). Wheat microsatellite markers (WMS) (Röder et al, 1998) are known to be abundant, highly polymorphic, reliable and relatively easy in application, and have already been used in several studies to estimate the genetic diversity in wheat (Salem & Mattar, 2014). Molecular marker-based diagnostics have emerged as a potential tool to screen wheat germplasm for using in incorporating resistance against CCN in wheat cultivars (Erum et al, 2013).…”