文献类型：期刊文献

英文题名：Precocious genotypes and homozygous tendency generated by self-pollination in walnut

作者：Chen, Lingna[1,2] Dong, Runquan[3] Ma, Qingguo[1] Zhang, Yu[3] Xu, Shizhong[4] Ning, Delu[3] Chen, Qin[3] Pei, Dong[1]

通信作者：Pei, D[1]

机构：[1]Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Key Lab Tree Breeding & Cultivat, State Forestry & Grassland Adm,Res Inst Forestry, Beijing 100091, Peoples R China;[2]Chinese Acad Forestry, Res Inst Resources Insects, Kunming 650233, Yunnan, Peoples R China;[3]Yunnan Acad Forestry, Kunming 650204, Yunnan, Peoples R China;[4]Dali Forest Resource Management Stn, Dali 671000, Yunnan, Peoples R China

年份：2018

卷号：18

期号：1

外文期刊名：BMC PLANT BIOLOGY

收录：;Scopus(收录号：2-s2.0-85057783712);WOS:【SCI-EXPANDED(收录号:WOS:000451992000002)】；

基金：This project was supported by the National Natural Science Foundation of China (grant No. 31672126).

语种：英文

外文关键词：Juglans sigillata Dode; Juglans regia L; Self-pollination; Phenotype; Homozygosity; Juvenile period

摘要：BackgroundObservations of precocious (early bearing) genotypes of walnut (Juglans regia L.) under natural conditions encouraged us to study the origin and genetic control of these fascinating traits.ResultsIn this study, the self-fertility, progeny performance, and simple sequence repeat (SSR) locus variation of iron walnut (Juglans sigillata Dode), an ecotype of J. regia, were investigated. The average self-pollinated fruit set rate of J. sigillata cv. Dapao' (DP) was 7.0% annually from 1979 to 1982. The average germination rate of self-pollinated seeds was 45.2% during the 4-year period. Most progeny had inbreeding depression. Nine representative self-pollinated progeny (SP1-SP9), with special or typical traits of DP, were selected. SP1-SP4 were precocious because they initiated flowers as early as 2years after germination, compared to the 7-10-yr period that is typical of DP. SP9 had not flowered since 1980. Twelve SSR markers were used to analyze the SP and DP. The genome of SP had a tendency toward high levels of homozygosity. The high levels of homozygosity reported in 18 additional precocious walnut genotypes complemented the results of this study.ConclusionsThese results provide evidence of precocious phenotypes and genomes with high levels of homozygosity that might be generated from self-pollinating walnut. This suggests that self-pollination might facilitate the generation of unique homozygous parents for subsequent use in walnut-breeding programs. The results also indicate that more attention should be focused on adequate management of precocious walnut to avoid early depression in the production of nuts.