Abstract:

SCAR(sequencecharacterized amplified region)marker primers SEA-F/SEA-R and SEB-F/SEB-R were designed on the basis of the DNA sequence of RAPD marker OPB-08₉₅₈ to obtain the SCAR marker linked to the precocious gene in walnut(Juglans regia). The reliability of SCAR-SEA₉₅₈ marker was detected by screening DNA from parents,hybrids and varieties(clone) with SEA-F/SEA-R primers. The results showed that the specific marker SCAR-SEA₉₅₈ was amplified stably using DNA extracted from precocious parent ‘Lüyuan’ as the template with SEA-F/SEA-R primers. In the F₁ hybrid population from ‘Lüyuan’בLüfeng’,the SCAR-SEA₉₅₈ marker was co-segregating with precocious gene of walnut and the genetic distance between SCAR-SEA₉₅₈ and precocious gene was 1.99 cM. To detect the reliability of SCAR-SEA₉₅₈ marker further, the template DNA from later mature maternal parent ‘T-12’, precocious paternal parent ‘Yanfeng’ and their 123 F₁ hybrids plants was screened with SEA-F/SEA-R primers. The SCAR-SEA₉₅₈ marker was co-segregating with precocious gene in the F₁ hybrid population from ‘T-12’בYanfeng’ either. In 9 walnut varieties(clone),the SCAR-SEA₉₅₈ marker was presented in 7 out of 8 precocious varieties, but absent in precocious variety ‘Luguang’ and later mature clone ‘T-12’.It was indicated that SCAR-SEA₉₅₈ would be an identifier of precocious walnut varieties(clone). Stability of the effect of SCAR-SEA₉₅₈ was high in different genetic backgrounds.

Key words: walnut (Juglans regia), precocious trait, RAPD, SCAR