Study On Geographic Variation And Selection Of Hottuynia Cordata From Different Provenances

Based on provenance trials of Houttuynia cordata of 23 provenances originated from Jiangxi, Guizhou, Fujian, Yunnan, Zhejiang, Henan, Hunan, Guangxi, Chongqing, Sichuan, Anhui Province, main agronomic characters, mophylogical characters, RAPD markers and main secondary metabolites of the planted H. cordata were studied which aimed to reveal the genetic diversity and genetic variation of Houttuynia germplasm resources and provide a foundiation for breeding excellent cultivars of H. cordata. The major results were as follows:1. There were significant variations in leaf, flower, fruit and aerial stem of H. cordata from different provenances. The leaf style and flower or fruit number varied most, the plant height was followed. According to the main mophylogical characters, 23 provenances could be divided into 2 types. The plants those were characterized with green leave and long internodes at the early growth stage, and emerald green leaves and wavy, high plant height, long infructescence, short pedicel and many flower or fruit(more than 2)at the rapid or late growth stage were referred to as type 1 while the plants characterized with red leave and short internodes at the early growth stage, and blackish green leaves and nearly smooth leaf edge, low plant height, short infructescence, long pedicel and few flower or fruit(less than 2)at the rapid or late growth stage were referred to as type 2. The study results of RAPD markers and main secondary metabolites supported the division of 2 types.2. There was significant difference among provenances in main secondary metabolites including major volatile oils and flavonoids. Some uncommon secondary metabolites could even distinguish the types and the provenances of H. cordata. The relationship between volatile oils which had zonal or geographic variation and morphological characteristics was much closer than the one between flavonoids and morphological characteristics. Houttuynia germplasm played a decisive role of the differences in major secondary metabolites.3. Considering total contents of flavonoids, total content of volatile oils, content of methyl-n-nonylketone and yield, H. cordata from Zhejiang Changxing, Zhejiang Shengzhou and Zhejiang Jiashan provenances should be superior than the ones from other provenances if be cultivated in Zhejiang.