A Comparative Study On Yield And Quality Of Different Chalky Rice Types In Saline - Alkali Soil

To clarify the difference of yield and quality among different chalkiness rice, in this study,wegrew9japonica rice varieties with different chalky grain ratesin Heilongjiang BayiAgricultural University paddy-bases (salt-alkaline soils) based on completely randomized design,and compared the agronomic traits, physiological characteristics, seed yield and quality. We triedto reveal the relationship between chalkiness and yield/quality.The main results in this study areas follows:1. Rice varieties with different chalkinesstypes displayed differently in yield and yieldcomponent factors.Specifically speaking, the panicle numers per square meter of low chalkinessrice were35.03%higher than that of medium chalkiness rice, however, the grain numbers perpanicle were53.77%lower than that of medium chalkiness rice. Furthermore, the thousand-grainweight and yield of the high chalkiness rice were significantly higher than that of the lowchalkiness varieties. It is worth to note that among different rice varieties, the chalky grain rateand chalkiness were significantly or extremly significantly negativecorrelated to the seed settingrates. As for the high chalkiness rice varieties,the chalky grain rate and chalkiness wereextremlysignificantly positive correlated with the solid thousand-grain weight of superior, middleandinferior grains.2. The numbers of panicles and middle-/lower-secondary branches were obviously differentamong different chalkiness rice.For example, the high chalkiness rice showed the most panicles,and the medium chalkiness rice displayed the least panicles.The panicle numbers of themediumchalkiness rice was44.15%and41.07%less thanthat of the high and low chalkinessrice,respectively.Contrarily, the numbersof middle and lowersecondary branches were highestfor the medium chalkiness rice but lowest forthe low chalkiness varieties. The difference of themedium and low chalkiness rice reached a significant level.3. Thephysiological characteristicsamong different chalkiness rice at the tillering stage showedno obvious difference, including leaf area index, dry weight, functional leaf SPAD value andphotosynthetic indices. However, obvious differences were observed atboth the full heading andfilling stage in leaf area index, dry weight and transpiration rate of functional leaf. In details, atthe full heading stage, theleaf area index of the high chalkiness rice was significantly lower (by 35.25%) thanthat of the medium chalkiness rice and33.72%lower than that of the lowchalkiness rice respectively, while the dry weight was53.37%and15.07%lower. At the fillingstage, theleaf area index of the high chalkiness rice was significantly lower (by20.86%) thanthatof the medium chalkiness rice and12.59%lower than that of the low chalkiness rice respectively,while the dry weight was31.78%and18.49%lower.4. The high chalkiness rice exhibited the highestmilled rice rates, which was2.60%and1.77%higher than medium and low chalkiness varieties, respectively.However, the high chalkiness ricedisplayed the lowesthead rice rate,4.91%and15.60%lower than medium and low chalkinessvarieties.Interestingly, we also found that the chalky grain rate and chalkiness were negativelycorrelated to head rice rate, but not significantly.In addition, the amylose content of the highchalkiness rice waslower than that of the medium chalkiness varieties, but higher than that of thelow chalkiness varieties. Notalby, the amylose content ofthe high chalkiness rice wassignificantly positively correlated withchalky grain rate and chalkiness (r=0.711**andr=0.682**).We did not found obvious difference in the rice exterior, texture and taste valueamong different rice varieties.However, the low chalkiness rice varietiesdisplayed the highestvalue in peak viscosity, hot paste viscosity and cool paste viscosity, showing significantlydifference with the medium and high chalkiness rice varieties.