濒危植物新疆野苹果种子的萌发特性

Preliminary Exploration on Seed Germination in Endangered Plant Malus sieversii

新疆野苹果是珍稀的第三纪残遗植物。作为珍贵的果树种质资源,其具有抗寒性强、耐虫、耐病、耐旱等优良性状。本文研究了不同居群新疆野苹果种子萌发的生物学特性,研究表明,不同居群新疆野苹果种子的千粒重存在差异,红肉苹果（HR）〉巩留居群（GY）〉新源居群（XY）〉那拉提居群（NY）,其千粒重分别为26.86、25.63、23.58和19.76 g。种子经过去皮处理可以大大加快其萌发速度,其3 d后萌发率可达到100%;而室外低温层积种子在40 d后开始萌发,发芽率为85.67%;冰箱冷藏层积处理萌发速度最慢,60 d左右才开始萌发,发芽率为91.33%,从而推测影响新疆野苹果种子萌发的限制因素为种皮。0~3 a的种子可以保持较高的萌发力,萌发率可达87%以上;7 a的种子生活力急剧下降,萌发率仅为31.6%。红肉苹果发芽率最高,达到93%;新源居群次之;最低的为那拉提居群,仅为74%。

Malus sieversii is a tertiary relict plant. As a precious fruit germplasm, it has some excellent traits, such as stronger anti-cold ability, the resistance to insect, disease and drought. In this paper, the biological characteristics of seed germination in different populations of Malus sieversii were explored. The results show that 1 000-seed weight varied among different populations, and those of HR were the heaviest （26.86 g）, subsequently with GY population （25.63 g）, XY population （23.58 g） and NY population （19.76 g）. By comparing three different methods of seed germination, it is concluded that the germination rate was much higher with removing the seed coat, reaching to 100% after 3 days. However, the seeds stratified outdoor at low temperature started to germinate after 40 days, with germination rate of 85.67%. When treated in freezer at 4 ℃, the seeds germinated after 60 days, with germination rate of 91.33%. The seed coat could be the main limiting factor for its germination. According to the study, it is can also be concluded that seeds stored for less than 3 years have higher germination rate of over 87%, seeds stored for 7 years dropped prominently to 31.6%. These results also show that germination rate in HR population was the highest （93%）, followed by XY population, and that in NY population was the lowest （74%）.