Study On The Phenology And Seed Ecology Of Four Suaeda Species In Xinjiang

The reproductive characteristics of Suaeda linifolia, S. salsa, S. paradoxa and S. kossinskyi were elementarily studied both in the field and indoor in the Junggar desert. The characteristics of phenology, seeds types and morphology and germination of the four species in Suaeda were studied, the results are as follows:(1) The life history of the four species in Suaeda was eight months. The objective vegetative growth phases was 87-90 days in 2008 and was 61-64 days in 2009, which were much longer than the reproductive growth phases. The flowering has the characteristic of persistence.The vegetative growth phases occurred at the same time with the reproductive growth phases.(2) There was seed polymorphism in seeds of four species of Suaeda. The morphs, size, color and mass of fruits of two types were significantly different, Brown seeds of Suaeda linifolia, S. salsa, S. paradoxa and S. kossinsky were flat with membrane seed coat while black seeds of the four species was lenticulated with chitin seed coat. Besides, the size and mass of brown seeds was larger than that of black seeds.(3) Germination of brown and black seeds were different and germination percentages of brown seeds were significantly higher than that of black seeds at four temperature regimes (2/15℃,10/20℃,15/25℃,25/30℃, Dark/Light=12 h/12 h). Germination percentage of S. salsa was higher than 80% only at 25/30℃while that of other three species were less than 80% at all temperature regimes, this phenomenon indicated different dormancy characteristics between the two seed types. Because cold stratification or scrafication could improve germination of brown seeds and a portion of black seeds of four species in Suaeda, so the dormancy of black seeds was deeper than that of brown seeds.(4) The capitulums of S. Linifolia was comprised of three flowers which was formed at axillae and the spike was comprised of capitulums which were formed at branches. The whole stage of flowering of S. linifolia is from June to September.The flowers bloomed from base to distal on individual plant and branch while the middle flowers bloomed 10-15 days earlier than flowers on two lateral sides of a capitulum. The middle flowers developed into black seeds and the seeds dispersed one month later after maturation, while flowers on two lateral sides of capitulum developed into brown seeds and matured from the end of September or the beginning of October and could not disperse, The ratio of brown seeds and black seeds was 2:1.