播期及温度对紫两优737农艺性状、品质和类黄酮含量的影响

Effects of Sowing Time and Ambient Temperature after Heading on Agronomic Traits and Grain Quality/Flavonoid Content of Ziliangyou 737

【目的】通过分期播种紫两优737,分析播期和灌浆期温度变化对紫两优737农艺性状、品质和类黄酮等含量的影响,为紫两优737的优质高产栽培提供技术支持。【方法】以紫两优737为材料,分期播种和种植,对紫两优737始穗后7、10、14、21 d环境温度变化和成熟期的农艺性状、品质及类黄酮含量等进行比较分析,并对相关关系进行回归分析。【结果】随着播期的推迟,有效积温EAT(Effective accumulated temperature)逐渐降低;紫两优737的株高降低,穗长随着播期的推迟先增加后逐渐减小。结实率和产量先降后升。始穗后10 d内的高温时数∑H(High temperature hours)、时热积温∑Th(Thermal accumulated temperature hour)严重影响水稻结实率;始穗后14 d内的日均温TA(Average temperature)对结实率也影响很大,当TA为31.645℃时,结实率最低,但是随着温度的升高,影响趋缓;始穗后21 d的日热积温∑Td(Daily thermal accumulated temperature)会造成水稻空瘪粒从而导致结实率下降。维生素含量与分期播种无明显相关,维生素绝对值较高的是VB_(5)、VB_(6)和VB_(2)。随着播期的推迟,直链淀粉含量直线下降,直链淀粉含量受∑H、∑Td、∑Th影响,温度与直链淀粉含量显著正相关,后期高温对直链淀粉含量影响趋缓。在福建晚稻地区,TA控制在26.84℃以下,对于保持糯稻的品质较好;花青素和黄酮含量随播期推迟逐渐增加;随着播期推迟,种皮颜色由棕红色变为深黑色,始穗后14 d至成熟,∑Td、TA和EAT对二者影响显著,温度的升高直接导致种皮变为棕红色,二者含量随之下降。【结论】在确保安全齐穗的基础上,生产中可以调整紫两优737播期,抽穗灌浆期TA控制在26.84℃以下,使EAT控制在2336.69~2390℃·d,福建晚稻对应播期6月15~25日可使产量和品质兼顾。紫两优737要合理安排在高海拔地区种植或者抽穗灌浆期TA较低的地区。

【Objective】Effects of seed sowing time and ambient temperature at grain-filling on the agronomic traits and rice quality/flavonoid content of Ziliangyou 737 were analyzed for improved the cultivation.【Method】Seeds of Ziliangyou 737 were sowed at intervals to vary the growing period and harvest season for studying the effects of sowing time and atmosphere temperature at grain-filling stage on the agronomic traits of the plants and quality and flavonoid content of the rice.In 7,10,14,and 21 d after start of grain-filling as well as at grain maturity,data were collected for a statistical analysis on the rice crops sowed on various dates.【Result】Under a shorter growing season,the plant height declined;the spike length became longer,then shorter;the seed setting rate and yield reduced,then increased;and the effective accumulated temperature(EAT)decreased gradually.TheΣH(High temperature hours)andΣTh(Thermal accumulated temperature hour)within 10 d after grain-filling significantly affected the seeding rate of the mature seeds,so did the TA(Average temperature)within 14 d after grain-filling.When TA was 31.645℃,the seeding rate reached the lowest level,but the effect was lessened with increasing ambient temperature as the grain matured.HighΣTd(Daily thermal accumulated temperature)at 21 d after initial filling resulted in higher rate of failed grain-filling which translated to a lower seeding rate.VB_(5),VB_(6),and VB_(2) were the vitamins in the greatest amounts found in the grains,but no significant correlation was found between vitamin contents and sowing time.Late sowing caused linear decline in grain amylose due to decreasedΣH,ΣTd,andΣTh.High temperature affected the amylose content positively,but the effect was less at the late filling stage.Controlling TA at a level below 26.84℃could help maintain the quality of the waxy rice crop sowed in late season in Fujian.The contents of anthocyanins and flavonoids correlated to the sowing time as shown by the color of seed hull that changed from reddish brown to dark black.From 14 d after grain-filling till maturity,ΣTd,TA,and EAT became extremely significant factors in the color change as a rising temperature mitigated anthocyanins and flavonoids.【Conclusion】Scheduling of Ziliangyou 737 sowing significantly affected the growth and grain quality of the waxy rice.By controlling a TA less than 26.84℃and an EAT at 2336.69-2390℃·d during grain-filling,crop yield and rice quality could be maximized.In Fujian,sowing between June 15 and 25 would thus be desirable.For other localities,cultivation in areas at high altitude or those that provide low TA at grain-filling stage would be recommended for Ziliangyou 737.