【作者】 蔡一霞；

【导师】 朱庆森； 杨建昌；

【作者基本信息】 扬州大学 ， 作物栽培学与耕作学， 2001， 硕士

【摘要】 通过严格控制土壤水分的盆栽以及大田试验，研究了常规粳稻武香粳9号和三系杂交籼稻汕优63结实期不同低限土水势对稻米品质主要性状整精米率、垩白及直链淀粉含量等指标的影响及其生理特性；并观察了严重水分胁迫下不同品种稻米品质性状的变化，结果表明： （1）水稻籽粒整个灌浆结实期间，当低限土水势为—15kPa时，稻米品质有所改善；而当低限土壤水势低于—15kPa时，整精米率显著降低，垩白粒率、垩白度显著提高，对胶稠度的影响表现出二次曲线的关系，而对粒形、直链淀粉含量和粗蛋白影响较小，处理间差异不显著。 （2）在籽粒灌浆期，不同土壤水分处理稻株的颖花绿叶量、叶绿素含量、籽粒含水量等生理指标明显变化，低限上水势≤-30kPa，灌浆中后期（花后25～35天）的颖花绿叶量和叶绿素含量的相对增量表现出明显的负效应，籽粒失水较快，从而影响米质形成期光合生产和籽粒中淀粉的积累，最终导致米质变劣，整精米率显著下降，垩白粒率和垩白度显著增加。 （3）严重水分胁迫对稻米加工、外观及蒸煮和营养品质均有不同程度的影响，不同基因型品种表现不同。整精米率在严重水分胁迫下有提高的趋势，部分品种显著提高；垩白粒率和垩白度的变化因品种类型而异，籼稻品种的垩白粒率和垩白度有降低的趋势，而粳稻品种却有升高的趋势；品种的粒长、粒宽呈减小趋势，部分品种显著减小，对粒形的影响是建立在粒长和粒宽共同变化的基础上；胶调度的变化比较复杂，品种间无规律可寻；而对出糙率、精米率、糊化温度（碱消值）、直链淀粉含量和蛋白质含量无显著影响。2 蔡一霞 土壤水分对稻米品质形成的影响 O）严重水分胁迫显著影响每穗粒数、受精率、干粒重和结实率等穗粒性状，不同品种在严重水分胁迫下穗粒性状的变化差异显著，主要表现在每穗粒数、饱粒千粒重和受精粒千粒重上，对扬旱1号、白珍珠、北农95－2和旱6－235变幅较小。 …）严重水分胁迫对稻米淀粉RVA谱有极显著的影响，且不同品种受影响的情况存在显著差异。除穗粒性状受土壤水分影响较小的4个品种外，淀粉粘度谱特征值最高粘度、热浆粘度、最终粘度以及崩解值旱种时有减小的趋势，而消减值却呈现增加的趋势。根据RVA谱三个特征值（崩解值、回复值和消减值）变化，可将参试品种分为 4类，扬旱 1号、白珍珠、北农 95工和旱 6235这 4个品种在“旱种条件下食味品质有所改善。更多还原

【Abstract】 ~J~HK~ 2001 ~眫4~ti~ 3 EFFECTS OF SOIL MOISTURE ON THE DEVELOPMENT OF RICE QUALITY Postgraduate: Cat Yixia Supervisor: Prof Zhu Qingsen Prof Yang Jianchang (Agri. College, Yangzhou Univ. Yangzhou 225009) ABSTRACT The experiments were carried out in the pot and filed by rigorously controlling soil water potential with tensionmeters. With Wuxiangjing 9 (a Japonica variety) and Shangyou 63 (an Indica hybrid rice combination) as materials, the effects of different soil water potentials on the main quality characteristics of rice , such as head milled rice, chalkiness, amylose content, and physiological characters were studied, and the changes of quality characteristics in different genotype-rice under heavy water stress were observed. The main results were as follows: 1. During the grain filling period, when the soil water potential (SWP) was reduced to -1 5kPa, the grain quality was improved; while SWP was under -1 5kPa, head milled rice was significantly decreased, both the percentage and degree of chalkiness were significantly increased, there was a conic relationship between gel consistency and SWP, and there was no significant difference among treatments in other quality indices, such as kernel shape, amylase content and protein content. 2. There were obviously changes in spikelet-leaf ratio, chlorophyll content and grain water content during grain-filling period. If the low soil water potential was under - 3OkPa, the relatively increased amounts of spikelet-leaf ratio and chlorophyll content were presented negative effects during the 25?5 days after flowering, dehydration of kernel was very rapid. 3. Under heavy water stress, there was a increasing trend of head milled rice, some varieties were significantly increased; chalkiness varied with cultivars, there was a 4 decreasing trend in indica cultivars and an increasing trend in japonica cultivars; the effects on kernel shape were based on the changes of both kernel length and kernel width; gel consistency was complex, and no regulations could be gained; and there was no significant difference in other indices such as brown rice, milled rice, pasting temperature (alkali spreading value), arnylase content and protein content between heavy water-stressed and well-watered treatment. 4. Some properties of ear and grain were significantly affected by heavy water stress, and varied with genotype, especially in the number of spikelets per panicle, iO~- grain weight, fecundated-grain percentage and filled-grain percentage. There were 4 varieties (yanghan 1, baizhenzhu, beinong95-2 and hang6-235 ) whose properties were not obviously affected by heavy water stress. 5. Heavy water stress significantly affected rice starch viscosity proflles(tested using a Rapid Visco-analyzer, RVA), and there were obvious difference between genotype varieties. There were decreasing trends of RVA profile character such as peak viscosity, hot viscosity, cool viscosity and breakdown in most varieties under heavy water stress, while an increasing trend of consistence in most varieties. According to the changes of breakdown, setback and consistence, the varieties tested could be sorted for 4 groups. The gra更多还原