紫花芒果NPKCaMg叶片诊断的DRIS标准初步研究

按诊断与推荐综合系统（DRIS）标准建立的常规方法.通过比较低产和高产组叶片N、P、K、Ca、Mg养分含量以及两元素间的养分比和养分积，初步筛选出N／P、N／K、N／Ca、N／Mg、K／P、Ca/P、P／Mg、K／Ca.K／Mg和Ca／Mg作为DRIS参项，并初步提出紫花芒果DRIS诊断标准.

Effects of different mechanical direct seeding methods on grain yield and lodging resistance of early indica rice in South China

Direct seeding of rice has become a main planting method due to the low labor input and high economic benefit in South China.Dry direct seeding(DDS)has been widely used for single-season rice planting establishment.However,few studies have examined the performance of early-season indica rice under mechanical dry direct seeding.A two-year field experiment was conducted with two indica rice cultivars(i.e.,Zhongjiazao 17 and Zhuliangyou 819)to study lodging characteristics and grain yield formation under DDS,flooded direct seeding(FDS)and wet direct seeding(WDS)patterns.The results showed that the annual grain yield in DDS was higher by 14.42–26.34%for cultivar ZLY819 and 6.64–24.58%for cultivar ZJZ17 than in WDS and FDS,respectively,and these increases were mainly attributed to the improvement of the panicles.The DDS pattern significantly increased the seedling emergence rate of early indica rice cultivars,and increased total dry weight and crop growth rate.Meanwhile,shorter basal internodes,better stem diameter and stem wall thickness and lower lodging index were found in DDS in contrast to FDS and WDS.In particular,DDS improved the stem lodging resistance.Our results suggested that the appropriate direct seeding method was beneficial for improving the grain yield and lodging resistance of early indica rice.

Effects of Different Irrigation Management on the Textural Properties of Double-Cropping Late Indica Rice in South China

In order to investigate the effects of different irrigation management on the textural properties of two different double-cropping late indica rice,the effects of three irrigation management including conventional irrigation(CK),constant irrigation(CI)and alternate wetting and drying(AWD)on textural properties has been researched under field conditions of two years.The results indicated that the firmness,cohesiveness and chewiness were decreased under AWD treatment,and the stickiness was increased compared with CK,while the textural properties under CI treatment showed the opposite trend with AWD treatment.Additionally,AWD treatment signifi-cantly improved the springiness of TY871 compared with CK and CI treatment,but had no significant effect in RYHZ,suggesting improvement of the cooking and eating quality of TY871 under AWD treatment.Correlation analysis showed that the chewiness was positively correlated with the firmness and cohesiveness,and the cohesiveness was positively correlated with the firmness.AWD could promote the textural properties of high-quality late indica rice in South China whereas CI treatment has shown the disadvantage of the textural properties,which will provide useful information for the improvement of cooking and eating quality of rice.

云南干热籼稻区水稻高产形成规律及群体质量指标研究

为鉴定杂交籼稻组合在云南干热籼稻区种植的产量潜力,研究不同产量水平水稻产量形成规律及群体质量指标,选用大面积生产应用的6个杂交籼稻品种为材料进行了比较试验,并根据当地水稻生产特点制定了相应的高产栽培技术。结果显示,广优1186、德优4727、两优2186、宜优673、两优2161、宜香3003产量分别为15.65、15.29、15.19、15.18、14.89和13.95 t/hm^2。为更好的分析水稻高产形成规律,将6个品种产量划分为高产(13.0~14.0 t/hm^2)、更高产(14.0~15.0 t/hm^2)、超高产(15.0~16.0 t/hm^2)3个不同产量水平。超高产水稻较更高产水稻有效穗数提高10.25%,较高产水稻总粒数、实粒数、结实率分别提高32.13%、35.69%、12.50%;超高产水稻高峰苗数较更高产、高产水稻分别低10.32%和30.02%;成穗率随着产量水平的增加而增加。超高产水稻齐穗期总LAI为7左右,高效叶面积率70%左右。颖花量随着产量的增加而增加。超高产水稻实粒/叶、粒重/叶较高产水稻分别增加20.00%和25.54%。超高产水稻齐穗期、成熟期、齐穗至抽穗期干物质积累量较高产水稻分别提高11.70%、11.96%和12.35%。

Numerical Simulation of Root Growth Dynamics of CO_2-Enriched Hybrid Rice Cultivar Shanyou 63 Under Fully Open-Air Field Conditions

Hybrid indica rice （Oryza sativa L.） cultivars play an important role in rice production system due to its heterosis, resistance to environmental stress, large panicle, and high yield potential. However, no attention has been given to its root growth dynamic responses to rising atmospheric CO2 concentration （[CO2]） in conjunction with nitrogen （N） availability. Free air COz enrichment （FACE） and N have significant effects on rice root growth. In this experiment, a hybrid cultivar Shanyou 63 （Oryza sativa L.） was used to study the effects of FACE and N levels on roots growth of rice. The results showed a significant increase in both adventitious root volume （ARV） and adventitious root dry weight （ARD） under the FACE treatment. The application of nitrogen also increased ARV and ARD, but the increase was smaller than that under FACE treatment. On the basis of the FACE experiment, numerical models for rice adventitious root volume and dry weight were built with the time as the driving factor. The models illustrated the dynamic development of rice adventitious root volume and dry weight after transplanting, regulated either by the influence factor of atmospheric [CO2] or by N application. The models were successfully used to predict ARV and ARD under FACE treatment in a different year with the predicted data being closely related to the actual experimental data. The model had guiding significance to growth regulation of rice root under the condition of atmospheric [CO2] rising in the future.