Pedigree analysis of grape cultivars released in China

Abstract：【Objective】In order to provide a theoretical foundation for future selection of parents andbreeding of new grape varieties in China, the survey of grape varieties bred in China from 1959 to 2015 were overviewed and summarized, their parents’origination and combination rule were analyzed based onthe pedigree data.【Methods】Information enquiry and websites were used to trace the parents of releasedcultivars until the original parents. The genetic contribution of ancestral parents for each released cultivarwas calculated based on the deduced original parents. The calculation method for genetic contribution byoriginal parents was based on the method used by Gai Junyi et al., with slight modifications. The geneticcontribution value of all the cultivars of parents bred through natural selection was 1 and that of the cultivars of parents bred through conventional cross was 0.5. The calculation methods of genetic contributionvalue for all the parent varieties bred through the sport selection and induced mutation were the same asthe parent varieties bred by natural selection. The parents of every parent were deduced till to the ultimateoriginal parents according to the equal segmentation methods.【Results】From 1959 to 2015, there were316 grape cultivars released in China. Among them, the parental records of 7 cultivars are unclear; hence,statistical analysis was only carried out in the remaining 309 cultivars that have clear parental sources.These 309 cultivars were classified based on their uses and breeding routes. Grape cultivars can be classi⁃fied into hybrid breeding, bud breeding, seed breeding and mutation breeding, which are 207, 64, 34, and4 cultivars, respectively. Grape cultivars can be divided into table cultivars, wine production cultivars,rootstock cultivars, and processed cultivars based on their uses, which occupy 74.5%, 19.4%, 3.2%, and2.9% of grape cultivars, respectively. In China, grape new cultivars mainly consist of table grapes, and oth⁃er cultivars showed small increases as market demand of diversification. The main breeding methods ofgrape cultivars in China is hybrid breeding. 309 cultivars could be ultimately traced to 118 ancestral parents, of which 8.5% were wild grape species, 76.3% were imported cultivars, and 15.2% were cultivarswith unknown origins, and their corresponding genetic contribution rates were 14.4%, 82.2%, and 3.4%,respectively. Among all the original parents, the number of cultivars produced by 5 parents was more than150, with a genetic contribution rate of 32.1%, these five grape cultivars were‘Muscat a Petits Grains’‘Heptakilo’‘Blauer Trollinger’，V. labrusca and‘Semillon’. The 164 direct parents consists of domesticwild species, exotic cultivars, domestic cultivars, and unknown cultivars, which are 6.1%, 12.2%, 73.2%,and 8.5%, respectively‘. Muscat Hamburg’and‘Kyoho’were used as direct parents for selective breedingof 90 breeding cultivars, which is 28.9% of all grape cultivars. Ancestral parents mainly consist of imported grape cultivars, while direct parents are mostly breeding cultivars. Wild grape species are still notgreatly valued during the grape breeding process in China, and its uses still face great limitations. Compared with 1959—1999, the number of ancestral parents and direct parents of breeding grape cultivarswas increased by 1-fold in 2000. Although the number of parents was higher, its genetic contributionswere focused in a small number of original parents. This is due to the high usage frequency of direct parents, and a large number of cultivars were bred from few superior parents, and the genetic basis of thesenew species is correspondingly narrow.【Conclusion】The main foundation parents of grapes in China are‘Muscat Hamburg’and‘Kyoho’. At the same time it was found that grape cultivars with disease resistance, larger size, and rose aromas are important research directions to the grape breeding industry in China. These results can preliminarily confirm the breeding objectives of grape cultivars in China, so as toguide the grapes breeding.