Selection Of New Chinese Bayberry Varieties And Investigation On Salt Tolerance Of Different Cultivars In Yuyao Coastal Region

Chinese bayberry (Myrica rubra Sieb.&Zucc.), native to southern China, which not only can be used as a natural green healthy food, but also as forestation and urban planting tree. China has abundant bayberry germplasm resources with many local varieties, but the new cultivars of large scale cultivation are limited. This study reported the first crossing breeding case and constructed the bayberry genetic linkage map. It will provide basis for subsequent bayberry germplasm resources research and functional gene location. Five new lines with potential market competitiveness had successfully been selected. We also investigated the adaptability of bayberry in Yuyao coastal area of saline-alkali soil in order to introduce the production of bayberry in this region. The main results were summarized as followings:1. Construction the frame genetic linkage map of bayberry hybrid populationFor a long time, bayberry breeding was mainly depended on natural elite lines. In this study, we attempted to cross between two cultivars,’Biqi’as female parent and ’Dongkui’ as male parent. We harvested 160 hybrid seeds,117 of which were seedling emergence, and ultimate survival of 109 seedlings. By using eight polymorphic SSR makers we identified 83 seedlings were as true hybrids. The UPGMA dendrogram tree showed that 39 offspring were closely related to father’Dongkui’, and 44 offspring were closely related to’Biqi’that showed the partial maternal heridity.The linkage map was constructed in cross population using JOINMAP 4.1. The map comprised 89 SSR makers on the eight linkage groups, and spanned 415.6 cM with an average marker distance of 5.1 cM.2. The selection of new bayberry varietiesWe surveyed 54 accessions of bayberry germplasm resources and measured the fruit characteristic of 40 bayberry varieties, among them we found five accessions ’Xiazhihong’, ’Y2010-70’,’Y2012-136’,’Y2012-145’and’Y2015-4’with good fruit quality. The botany characteristics, phenophase, fruit quality, and SSR marker fingerprint between the five excellent accession and local cultivars had been compared. Mature period of ’Y2010-70’,’Y2012-136’ was 10 days earlier than’Biqi’which could extend bayberry picking time and increase industry competitiveness. Finally, we analyzed the genetic relationship among 148 bayberry accessions. It would provide theoretical basis for bayberry breeding and genetic diversity research.3. Investigation on salt tolerance of different cultivars in Yuyao coastal regionChina has a large area of saline-alkali land, especially in the east coast. In Yuyao area, the bayberry main producing region, distributed in mountainous area, not in plains and coastal areas. To increase production in coastal areas, we investigated the salt-tolerant of four bayberry cultivours and tested different methods to improve the soil condition. Finally, we found’Biqi’ showed the best salt-tolerant among the four cultivars. We also confirmed an effective method which could reduce soil pH value and improved the content of organic matter.