Study On Different Temperature Typical Wheat' Source-sink Characteristics And Their Relationship

The experiment was conducted at the Agronomy Research Farm, NWSUAF over two consecutive years( 1999-2001) to study different temperature typical wheat' source-sink characteristics and their relationship after anthesis. The main results as follows:(l)The duration of Cold Typical Wheat (CTW)'s leaves are longer, their photosynthesis are stronger, matter stored transfers less, weight of leaves, stems and sheaths begin to reduce later and less than Warm Typical Wheat (WTW).(2) CTW's bleeding intensity below spike is higher than WTW during grain formation and filling stage, especially at later stage. CTW's vascular bundle number and area per weight per ear are higher than WTW. That is, CTW has better transporting tissue than WTW, CTW's matter transports better than WTW at later stage.(3)CTW's grain peak filling rate is lower, but its duration of high filling rate is longer, and the matter accumulated at middle and later stages are more, and its grain volumn shrinks less.(4)The grain at different positions of different type is alike with the whole ear grains of identical type. M32 which grows earlier, replenish greatly has higher peak filling rate, at the same time its sink capacity is the more most, thus, M32 is not plumer than the light-weight grains contrarily.(5)CTW's soluble sugar density, starch density and starch composing rate are all higher. CTW's grains are more active than WTW's. For grains of different position in a ear, M32 is more lively.(6)CTW's grains are plumper, their setting kernels whenever contrasting or source-sink altering are both more too.(7)The grain filling rate is influenced by the green leaves area and photosynthetic rate after anthesis. Grain weight is determined by the dry matter amount accumulated after anthesis above ground. The dry matter amount changing of leaves, sterns and sheaths affects grain filling rate greatly. CTW's source coordinates with its sink. That is, CTW's source-sink relationship is more harmonious than WTW's.