苹果实生砧木资源重要性状的遗传多样性分析

Genetic diversity in morphology,stress tolerance and graft-compatibility among species,ecotypes and their segregation within populations of apple rootstock resources

【目的】为了解苹果实生砧木资源重要砧木性状的种间、居群间和株系间差异及株系内性状分离,【方法】搜集了7个种21份苹果资源的种子,建立实生群体,播种当年调查实生苗株高、干粗、叶形指数和分枝数等形态性状,当年秋芽接富士和金冠品种,第2年调查实生苗越冬抽条率、耐盐性、嫁接芽萌芽率、抽梢率和成苗率。通过接种鉴定评价腐烂病和轮纹病的抗病性。【结果】形态性状种间差异显著,平邑甜茶形态一致性好。1 a生实生苗耐越冬抽条能力种间差异大。栽培品种实生苗耐抽条能力差,且易感苹果轮纹病。八棱海棠和平顶海棠耐盐碱性较强,山定子耐盐碱性差,且居群间差异极显著。腐烂病和轮纹病的抗病性均存在种间、居群间或株系间差异及严重的株系内性状分离。平邑甜茶和小金海棠的嫁接芽抽梢率和秋季成苗率均低。【结论】多数性状不仅种间、居群间或株系间差异显著,株系内性状也严重分离。选育、应用苹果无性系砧木是迫切需求。

[Objective]Germplasm resources of apple rootstock in China are extremely abundant. Twenty - one kinds of seeds belonging to 7 species were collected to build the seedling populations to investigate differences of main rootstock traits among species, populations and strains, and segregation within strains. [Method]Morphological characters of seedlings were measured in the first year after sowing. These char- acters include plant height, stem diameter, leaf shape index and branching number. ＇ Fuji＇ and ＇ Golden Delicious＇ were grafted on the seedlings by budding in autumn of the first year. The over wintering physio- logical drought, saline-alkaline tolerance, sprouting rate, shooting percentage of grafting bud and plant- let formation rate were investigated in the second year. The resistance of plants to canker and ring spot were also evaluated by using inoculating identification. [Result]The results showed that morphological traits among species differ significantly, and M. hupehensis had good conformity. The endurance of one- year-old seedling to physiological drought was found to differ significantly among species, while cultivar seedlings were less tolerant to physiological drought. In addition, cuhivar seedlings were more susceptible to ring spot. The Baleng crabapple and ＇Pingding＇ crabapple were more tolerant to saline-alkaline, while M. baccata was more sensitive to saline-alkaline. Their saline-alkaline tolerances differ remarkably among populations. Canker and ring spot resistance of different apple rootstocks differs among species, popula- tions and strains, and the traits segregate severdy within strains. The shooting percentage of grafting bud