Fingerprinting and genetic purity assessment of F1 barley hybrids and their salt-tolerant parental lines using nSSR molecular markers

Abstract

Hybridity and the genuineness of hybrids are prominent characteristics for quality control of seeds and thereby for varietal improvement. In the current study, the cross between two local barley genotypes (Ardhaoui: female; Testour: male) previously identified as susceptible/tolerant to salt stress in Tunisia was achieved. The hybrid genetic purity of the generated F putative hybrids and the fingerprinting of the parents along with their offspring were assessed using a set of 17 nuclear SSR markers. Among the analyzed loci, 11 nSSR were shown polymorphic among the parents and their offspring. Based on the applied 11 polymorphic SSR loci, a total of 28 alleles were detected with an average of 2.54 alleles per locus. The locus presented the highest number of alleles. The highest polymorphism information content value was detected for the locus (0.6713) whereas the lowest PIC value (0.368) was revealed by the loci , and with a mean value of 0.4619. The probabilities of identical genotypes PI for the 11 microsatellite markers were 8.63 × 10. Banding patterns among parents and hybrids showed polymorphic fragments. The 11 SSR loci had produced unique fingerprints for each analyzed genotype and segregate between the two parental lines and their four hybrids. Parentage analysis confirms the hybrid purity of the four analyzed genotypes. Six Tunisian barley accessions were used as an outgroup in the multivariate analysis to confirm the efficiency of the employed 11 nSSR markers in genetic differentiation among various barley germplasms. Thus, neighbor joining and factorial analysis revealed clearly the discrimination among the parental lines, the four hybrids and the outgroup accessions. Out of the detected polymorphic 11 nuclear SSR markers, a set of five markers (, ,, and) were shown to be sufficient and informative enough to discriminate among the six genotypes representing the two parental lines and the four hybrids from each others. These five nSSR markers presented the highest number of alleles per locus (), expected heterozygosity (), PIC values and the lowest probabilities of identity (PI). These nSSR loci may be used as referral SSR markers for unambiguous discrimination and genetic purity assessment in barley breeding programs.

Hybrid identification for Glycine max and Glycine soja with SSR markers and analysis of salt tolerance

“…In our present study, the similar banding patterns (Fig. 3) as Ben Romdhane et al (2018) were observed in the true hybrids, which are co-dominant SSR markers from both parents. However, the banding patterns of the false hybrids were only displayed in either female parent (P 1 ) (Fig.…”

“…The former, which is relied on the different phenotypic traits of hybrids and their parental lines, is considerably restricted for the limited intuitive agronomical traits, or because some agronomical traits can be detected only in the particular plant growth period, and some traits are very vulnerable to the environmental conditions. The assessment of genetic purity of hybrids via molecular fingerprinting or banding patterns of their parental lines based on SSR markers have been utilized in some crops, such as in maize (Hipi et al, 2013), rice (Bora et al, 2016), and barley (Ben Romdhane et al, 2018). In our present study, the similar banding patterns (Fig.…”

“…Identification of true hybrids was performed as previously described (Nandakumar et al, 2004; Ben Romdhane et al, 2018). If the sample of hybrids containing two parental co-dominant bands, could be judged as the true hybrid, otherwise could be false.…”

Peer Review #2 of "Hybrid identification for Glycine max and Glycine soja with SSR markers and analysis of salt tolerance (v0.1)"

“…The former, which is relied on the different phenotypic traits of hybrids and their parental lines, is considerably restricted for the limited intuitive agronomical traits, or because some agronomical traits can be detected only in the particular plant growth period, and some traits are very vulnerable to the environmental conditions. The assessment of genetic purity of hybrids via molecular fingerprinting or banding patterns of their parental lines based on SSR markers have been utilized in some crops, such as in maize (Hipi et al, 2013), rice (Bora et al 2016), and barley (Ben Romdhane et al, 2018). In our present study, the similar banding patterns (Figure 3) as Ben Romdhane et al (2018) were observed in the true hybrids, which are co-dominant SSR markers from both parents.…”

“…2 plant). The false hybrids may be due to unsuccessful hybridization, impure male parent and/or under an incompletely isolated pollination resulting in no parental pollen infiltration, and so on (Ben Romdhane et al, 2018).Thus, 30 true hybrids (accounting for 14.1%) were successfully obtained from the harvested 213 single hybrid plants of the designed 11 cross combinations, but a large difference of the proportion of true hybrid was PeerJ reviewing PDF | (2018:09:31658:1:2:NEW 20 Dec 2018)…”