抽穗前水分供应对寒地水稻品质的影响

以垦鉴稻5号和垦稻12号为材料,采用负压式土壤湿度计监测土壤水势,通过防雨棚内的盆栽控水试验,研究了抽穗前水分供应对寒地水稻品质的影响。研究结果表明,抽穗前进行-8～-10 kPa的间歇控水处理,有利于提高垦鉴稻5号的整精米率,不利于提高垦稻12号的整精米率;两品种的长/宽值呈减小趋势;两品种优势粒的垩白率和垩白度均有增加,两品种中势粒的垩白率和垩白度表现为减小,这有利于两品种直链淀粉含量的降低;两品种各粒位的蛋白质含量增加;二者优势粒的米饭食味评分值提高,中势粒的米饭食味评分值降低。结实前进行-18～-20 kPa和-28～-30 kPa的持续控水处理,有利于提高垦鉴稻5号的整精米率,不利于提高垦稻12号的整精米率;两种处理减小了两品种各粒位糙米的长和宽;减少了两品种的垩白率和垩白度;有利于两品种直链淀粉含量的降低;两种处理增加了两品种各粒位的蛋白质含量;两种处理降低了两个品种的米饭食味评分值。

Effects of Before-heading Water Supply on Quality of Rice in Cold Regions

With Kenjiandao 5 and Kendao 12 as experiment materials,the effects of before-heading water supply on the quality of rice in cold region were studied through pot planting in a rainproof chamber.The soil water potential(SWP) was monitored with negative pressure soil moisture tensiometers.The results show that with intermittent water control at SWP ranged from-10 to-8 kPa during the before heading stage,the whole rice rate was significantly improved for Kenjiandao 5 rather than Kendao 12,and the ratios of length to width decreased for the grains of both varieties.With the before-heading water control,the chalkiness rate and chalkiness degree were improved for the dominant grains and were reduced for the middle grains,implying possible reductions of amylose content for both varieties.Protein contents of all the grains of both varieties were enhanced,while the dominant grains received higher grades in regard to the taste and the middle grains had lower grades.With water controls at SWP of-18~-20 kPa and-28~-30 kPa before heading,the plants of the two varieties performed similar to those with the first treatment,except the chalkiness rate,chalkiness degree and taste grades were reduced for all the grains of both varieties.