Studies On The Sexual Reproductive Characteristics Of Mongolian Willow (Salix Linearistipularis)

Salix linearistipularis can grow in the Songnen Plain of saline soil with pH up to9.2, and the pH of the soil under bush roots is lower than the herb root, indicating that S. linearistipul-aris is not only with a strong salinity adaptability but also can influence and change the soil pH. So it is an valuable wild plant resource in saline-alkali soil improvement and applicati-on, and has great application value. However, there is not a lot of natural distribution of S. linearistipularis in the Songnen Plain saline soil, also rarely seedlings growing, and the rea-son is not clear. In this paper, with the S. linearistipularis growth in the Western Songnen Pl-ain salinization land as the object of study, by the methods of field observation, regular sa-mpling, artificial experiment, we explore the characteristics of sexual reproduction and the impact on species natural regeneration from the studying on the floral syndrome, pollination and fertilization, seed setting rate, seed vigor and other aspects, and we also provide a fav-orable scientific basis on the artificial breeding of S. linearistipularis.Our results as follows:(1) Floral syndrome:S. linearistipularis is dioecious plant, belonging to distance crossing (outcrossing) type. Blossom period is from mid April to early May, about20days. The nu-mber of single stamens pollen is about40000to56000, and the number of ovule of single p-istil is5to6. The life of S. linearistipularis pollen is about19days, and the receptivity pe-riod of pistil-stigma can last12to20days.(2) Pollination and fertilization:There are more than10kinds of flowervisiting insects in S. linearistipularis such as Apidae, Syrphidae, Calliphoridae and Chrysomelidae, etc.. The po-llen in the stigma can germinate in about2hours after successfully pollination, then a large n-umber of fertilized embryo germination after8hours.(3) Fruits and seeds:Once the fertilized embryo of S. linearistipularis development nor-mally, the fruit can being matured in about13days after fertilization, while sometimes the n-atural seed is also different because of the environment and climate change and its associate d f-actors, with76±7%in2011and83±9%in2012respectively, containing5-7pieces o f se-eds per fruit. The S. linearistipularis seeds can germinate in24h after shedding, and the y h-ave strong power of seed germination and the high rate of seedlings survival. The life o f S.linearistipularis seeds is about45days at room temperature, and the storage at low temper atur-e may be approp riate to extend the seeds of life.All in all, Salix linearistipularis can perform normal sexual reproduction, but the seeds are neither dormant nor short life. In saline-alkali soil environment, should be fresh ripe seeds cryogenic storage. And using of artificial way to get a lot of healthy planting seedling nursery stock, until the climatic and environmental conditions are suitable. So as to promote the improvement of soil population amplification and ameliorate saline-alkali soil.