Genetic similarities among winter wheat cultivars determined on the basis of RFLPs, AFLPs, and SSRs and their use for predicting progeny variance

The efficiency of breeding programs could be increased by predicting the pr ospects of crosses for line development before producing and testing lints derived from them. In this study, we (i) assessed the level of genetic dive rsity among German and Austrian winter wheat (Triticum aestivum L.) cultiva rs using 117 restriction fragment length polymorphism (RFLP) probes, 16 amp lified fragment length polymorphism (AFLP) primer combinations, and 21 simp le sequence repeat (SSR) primer pairs, (ii) investigated the correlation be tween coancestry (f) and genetic similarity (GS) estimated from molecular m arkers, and (iii) evaluated the use of f and GS for predicting the genetic variance (sigma(g)(2)) within sets of 22 F-4cn (n = 7 or 8) lines derived f rom 30 crosses between these winter wheat cultivars. The average polymorphi c information content (PIC) for polymorphic bands was not significantly dif ferent between the three marker systems (0.30 less than or equal to PIC les s than or equal to 0.33), whereas the marker index was low for RFLPs and SS Rs but high for AFLPs. Estimates off between all 55 cultivar combinations r anged from 0.01 to 0.53. <(GS)over cap>-values varied between 0.52 and 0.89 for RFLPs. between 0.40 and 0.83 for AFLPs. and between 0.16 and 0.91 for SSRs, The Mantel Z test statistic revealed no common pattern between the fo ur dendrograms obtained by cluster analyses. Significant (P < 0.05) correla tions among (f) over cap, <(GS)over cap>-RFLP, <(GS)over cap>-AFLP, and <(G S)over cap>-SSR were detected only for related parent combinations ((f) ove r cap greater than or equal to 0.10), For all seven traits analyzed, estima tes of sigma(g)(2) were not significantly associated with any measure of GS between parents. On the basis of these results, we recommend AFLPs for fin gerprinting wheat cultivars. However, predicting the progeny variance sigma (g)(2) remains an unsolved problem.