孕穗期自然低温对籼型杂交水稻的影响分析

孕穗期低温主要通过影响籼型杂交水稻结实率导致产量降低，对有效穗，每穗粒数和粒重无明显影响。在自然低温条件下，籼型杂交水稻组合间孕穗期耐冷性表现出明显的强、中、弱差异；进一步对亲本组合的分析发现，籼型杂交水稻孕穗期耐冷性与不育系和恢复系均有关，而与恢复系的关系更为密切：建议以低温影响后的结实率及其与正常结实率的差异程度作为评价水稻品种孕穗期耐冷性的指标。     

水稻对穗枯病的抗病机理初步研究

【目的】水稻在孕穗期比苗期更容易感染穗枯病(Bacterial panicle blight of rice)并出现病症。本研究旨在探究水稻不同时期对穗枯病的抗性机理,为培育抗病水稻品种奠定基础。【方法】采用喷雾法和注射法分别对苗期和孕穗期的抗、感病水稻品种接种颖壳伯克氏菌(Burkholderia glumae),测定处理组与对照组的3种抗氧化酶(POD、CAT、SOD)活性的差异,并利用实时荧光定量PCR测定5种防卫反应基因(PR1a、PR10b、Rcht、LOX、PAL)的表达量。【结果】B.glumae的侵染能引起水稻活性氧的积累,提高抗氧化酶活性,使部分防卫反应基因大量表达,但是苗期和孕穗期的应答有较大区别。水稻孕穗期的抗氧化酶(SOD、CAT和POD)活性和防卫反应基因(PR10b、Rcht和PAL)的表达量比苗期高,但PR1a和LOX的表达量却低于苗期。【结论】B.glumae能诱导孕穗期的水稻产生更多抗病反应,参与抗病反应的主要是水杨酸信号传导途径。     

不同供氮形态对旱作水稻生长和养分吸收的影响

采用土培试验种植旱作水稻,研究铵态氮（A）、硝态氮（N）和铵态氮加硝化抑制剂（A+DCD）对旱作水稻分蘖期、孕穗期生长和养分吸收的影响。在分蘖期和孕穗期,铵态氮和铵态氮加硝化抑制剂处理的水稻各部位生物量、分蘖数及新完全展开叶的叶面积均较硝态氮处理的高;铵态氮加硝化抑制剂处理的水稻叶片净光合速率最高,硝态氮处理的水稻叶片净光合速率最低; 铵态氮和铵态氮加硝化抑制剂处理的水稻体内的钾向叶片中分配比例较高,而硝态氮处理的水稻向茎秆中分配的比例较高。     

水稻叶片特异性不表达启动子pOsMTG3的克隆与表达分析

利用水稻基因芯片筛选到1个在水稻孕穗期和抽穗期穗中的相对表达量明显高于苗期、孕穗期和抽穗期叶片中相对表达量的基因Os MTG3,该基因在孕穗期穗中受低温、干旱诱导上调表达,而在抽穗期穗中受低温诱导下调表达。把该基因ATG密码子上游1.8kb左右的DNA片段预测为启动子区,并将其命名为p Os MTG3。用PCR技术克隆该启动子,并以GUS基因作为报告基因,在水稻中分析了该启动子在不同时期不同组织中的表达特性。GUS组织化学染色分析表明:p Os MTG3启动子能启动GUS基因在水稻根、芽、茎、穗中表达,而不能启动GUS基因在叶片中表达,是一个全新的叶片特异性不表达的启动子。     

黑龙江省水稻冷害产量试验模型研究

根据黑龙江省主栽品种的特点,选用了47个水稻品种,在人工气候室内进行孕穗期低温处理,最后调查每一个水稻品种的产量。孕穗期的处理条件为15℃、湿度80%、光照1.0万～1.3万lx,处理时间是1～7 d。以7 d水稻产量为标准,针对生态区域把材料划分为耐冷、较耐冷和一般耐冷3种类型。建立黑龙江省区域、第一、二、三积温带水稻冷害产量试验模型Y=Y0×(aX+b)。     

水稻应用速效钙效果研究

在水稻不同生育时期喷施不同用量的速效钙肥,可不同程度地加快水稻的生育进程,可增加水稻穗粒数、结实率和千粒重。在水稻孕穗期、齐穗期各施用速效钙17.5 g/667 m2的处理产量最高,增产率为7.7%。     

水稻耐冷性遗传及基因定位研究概况与展望

综述了水稻低温发芽力,幼苗期、孕穗期和开花期耐冷性等遗传研究概况和近年来在水稻耐冷性数量性状基因定位(QTLs)研究方面所取得的进展,并展望了今后的水稻耐冷性研究方向。     

水稻应用速效钙效果研究

在水稻不同生育时期喷施不同用量的速效钙肥,可不同程度地加快水稻的生育进程,可增加水稻穗粒数、结实率和千粒重。在水稻孕穗期、齐穗期各施用速效钙17.5 g/667 m2的处理产量最高,增产率为7.7%。     

不同淹涝胁迫强度对杂交中稻头季稻及再生稻生长的影响

以杂交中稻冈优725为试验材料,通过人工模拟"洪涝",研究了在水稻孕穗期、抽穗期、乳熟期不同淹涝胁迫强度处理对其生育期、叶绿素含量(SPAD值)以及产量构成的影响。结果表明,孕穗期和乳熟期淹没会明显推迟水稻的成熟期3~9 d,抽穗期淹没对成熟期影响较小,但在孕穗期和乳熟期淹没都有将再生稻成熟期提前的趋势;淹没不会引起叶片SPAD值的降低;在植株被全淹情况下,只要气温高于15℃,被淹没的水稻就不会因水温而影响其生长;不同淹水时期对杂交中稻头季稻产量影响程度表现为抽穗期﹥孕穗期﹥乳熟期,淹顶﹥淹没2/3;淹水时间越长,产量损失越大,总体上看,淹没36 h以上产量明显下降;单就对再生稻的影响而言,不同淹水时期对其产量影响程度表现为乳熟期﹥抽穗期﹥孕穗期,全淹没与淹没2/3处理间差异较小,不同淹水时间对再生稻产量的影响差异也不大。     

叶面喷施植物氨基酸液肥对水稻产量的影响

为了验证植物氨基酸液肥对水稻产量的影响,我们于2002年和2003年连续两年进行了水稻叶面喷施植物氨基酸液肥试验。试验结果表明,在水稻有效分蘖期、孕穗期和灌浆期各喷施一次植物氨基酸液肥,有效分蘖增加,可提高水稻产量14.11%。     

Comparisons of Metabolic Profiles for Carbohydrates,Amino Acids,Lipids, Fragrance and Flavones During Grain Development in indica Rice Cultivars

We used a widely targeted metabolomics approach to examine the metabolic changes in three pedigreed indica cultivars (Meixiangzhan 2, Meisizhan and Qixinzhan), with different eating qualities, at 8, 15 and 30 d after flowering (DAF) to explore the formation mechanism of rice eating and nutritional qualities at a global metabolic level. A total of 623 metabolites were identified, and results showed that metabolic variations among rice cultivars decreased with grain developmental stage, suggesting that sufficient carbohydrate and amino acid supply during grain development may contribute to excellent rice eating and nutritional quality formation. Lysophosphatidylcholines 19:0 and 16:1 were beneficial for excellent eating quality formation during grain development. Rice fragrance was attributed mainly to spermidine and γ-aminobutyric acid. Rice cultivars with excellent eating quality at 15-30 DAF had relatively higher flavone content, possibly because they had adequate carbohydrate and amino acid contents during grain development. These results provided insight into the mechanisms for establishing rice eating and nutritional qualities during grain formation at a global metabolic level, and can be applied towards improving rice quality.     

稻米糊化温度特性形成规律研究

利用差示扫描量热仪(DSC)对花后5 d起灌浆期间稻米糊化温度特性进行了研究。结果表明,糊化温度特性是随着谷粒的成熟而逐步形成的,表现出由高到低并逐渐趋于稳定的趋势。低糊化温度水稻品种黄玉B和高糊化温度品种Ⅱ32B的起始糊化温度(To)分别在花后第7 天和第9 天达到稳定,此后不再显著下降。两个品种花后5 d的稻米峰值温度(Tp)和终结温度(Tc)均极显著高于此后的稻米样本;花后7~25 d,黄玉B的Tp和Tc都出现了下降 上升 下降 上升的过程,但花后7 d和25 d的值没有显著差异;Ⅱ32B的Tc的变化与黄玉B相似,但其Tp只出现了一个下降 上升过程,且开花后7 d的Tp显著高于开花后25 d。这些结果表明,高、低糊化温度品种糊化温度特征的形成可能存在差异,在生产实践中,应该针对不同品种类型加以调控。     

Starch granules size distribution in superior and inferior grains of wheat is related to enzyme activities and their gene expressions during grain filling

Mature wheat endosperm contains A-, B-, C-type starch granules, and each class has unique physiochemical properties which determine the quality of starch. The dynamics of the starch granule size distribution, activities of starch synthases and expression of starch synthase encoding genes were studied in superior and inferior grains during grain filling. Compared with inferior grains, superior grains showed higher grain weight, contents of starch, amylose and amylopectin. The formation of A-, B-, C-type starch granules initiated at 4, 8, 20 DAF, respectively, and was well consistent with the temporally change patterns of starch synthase activities and relative gene expression levels. For instance, activities of soluble and granule-bound starch synthases (designated SSS and GBSS) peaked at 20 and 24 DAF. Genes encoding isoforms of starch synthases expressed at different grain filling periods. In addition, SS I was generally expressed over the grain filling stage; the SS II and SS III were expressed over the early and mid grain filling stage, and the GBSS I was expressed during the mid to late grain filling stage. In addition, the time-course changes in activities of starch synthases and expression of starch synthase encoding genes explained well the dynamics of the starch granule size distribution.     

完善我国农业“四补贴”政策的思考

概述我国农业“四补贴”(粮食直补、良种补贴、农机购置补贴、农资综合补贴)政策的实施现状,评价实施效果,分析存在的主要问题,提出完善我国农业“四补贴”政策的建议。     

冬小麦粒重形成与生育中期气象条件关系的研究

本文通过１９７４～１９９２年对小麦粒重形成与生育中期（拔节至抽穗）气象条件关系的研究,认为小麦开花后不久其粒重在年际间已有明显差异;小麦生育中期气象条件是影响早期粒重的重要因素,其中温度是影响的主导因素。每天日照在６ｈ以上易形成早期高粒重;降雨分布在该阶段的两端,有利于形成早期高粒重,这与生产上重视拔节与孕穗水是一致的;在早期粒重高的年份,最终粒重常常也高,因此,在生产实践中,采取有效措施提高早期     

Enhanced Nitrogen Uptake and Photosynthesis of Rice Grown with Deep and Permanent Irrigation Method: Possible Mechanism for Chalky Grain Reduction

Abstract

Recently, the occurrence of chalky grain caused by high temperature stress at the ripening stage has been a global problem for rice. We previously showed that the deep and permanent irrigation method, which is the combination of the V-furrow direct seeding and deep-flood irrigation methods, reduced chalky grain occurrence. To study the possible physiological mechanisms for reduced chalky grain occurrence by the deep and permanent irrigation method, we conducted field experiments in 2008 and 2009 to examine the effects of the deep-flood treatment on plant nitrogen (N) content, stomatal conductance and photosynthetic rate especially at the ripening stage. Results showed that in the deep-flood treatment that maintained a 20 cm water depth, leaf N content was consistently and significantly higher than the control with only a 10 cm water depth. Except two measured days, the stomatal conductance under the deep-flood treatment was significantly higher than in the control. Furthermore, stomatal conductance and photosynthetic rate in the deep-flood treatment were always significantly higher than in the control in both years. Thus, the deep-flood treatment enhanced N uptake, and consequently photosynthetic activity, resulting in the reduction of chalky grain formation, as previously reported. Accordingly, the effects of deep- flood treatment on grain quality improvement in rice may possibly be attributed to the improvement in source activity.     

不同土壤肥力条件下麦秆还田与氮肥运筹对杂交稻氮素利用、产量及米质的影响

以杂交稻F优498为材料,研究了高、低土壤肥力下麦秆覆盖与氮肥运筹对杂交稻主要生育期氮素吸收利用特征、产量及米质的影响,并探讨了不同土壤肥力下麦秆覆盖和氮肥运筹对结实期剑叶SPAD值与稻米品质的形成的影响。结果表明,不同土壤肥力下,麦秆覆盖均有效促进杂交稻各生育时期氮素积累,提高了氮素利用效率以及稻谷产量,增加了稻米蛋白质含量、稻米胶稠度,显著降低了稻米垩白度以及垩白粒率,且高土壤肥力下麦秆覆盖优于低土壤肥力下麦秆覆盖处理。同时,不同土壤肥力下麦秆覆盖处理,均以m基肥∶m蘖肥∶m穗肥为3∶3∶4的氮肥运筹模式最优,均能有效调节水稻灌浆结实期叶片SPAD值,提高水稻氮素吸收利用效率及稻谷产量;但稻米品质方面,高土壤肥力以m基肥∶m蘖肥∶m穗肥为5∶3∶2时最佳;而低土壤肥力可适当提高氮肥后移比例,以m基肥∶m蘖肥∶m穗肥=3∶3∶4最佳。相关分析表明,水稻灌浆期剑叶SPAD值与稻米出糙率、整精米率以及蛋白质含量显著或极显著正相关(r=0.47*~0.90**);与垩百度、垩白粒率负相关,但相关未达显著水平;而高土壤肥力下稻米品质各项指标分别与齐穗后19~27d剑叶SPAD值,低土壤肥力下麦秆覆盖与齐穗后13~19d剑叶SPAD值相关系数最大。     

"富农心"矿物元素增效剂在大豆上的应用效果初报

通过"富农心"矿物元素增效剂在大豆上的应用效果研究表明,施用"富农心"矿物元素增效剂有促进大豆健壮生长的趋势,但无增产效果。     

结实期土壤水分和氮素营养对水稻产量与品质的交互影响

杂交籼稻汕优63和粳稻武育粳3号种植于土培池,于始穗期进行0N（0 g/m2）、NN（中氮,4.5 g/m2 ）和HN（高氮,9.0 g/m2）3种施氮量处理,于抽穗后7 d至成熟期设置了WW（保持浅水层）、MD（轻度落干,土壤水势保持-25 kPa）和SD（重度落干,土壤水势保持-50 kPa）3种土壤水分处理,研究了结实期土壤水分和氮素营养对水稻产量与品质的交互影响。在各施氮水平下,产量、糙米率、精米率和整精米率均以MD处理最高,垩白粒率和垩白度均以MD处理最低。在0N下,SD处理降低了产量、碾磨品质、外观品质和食味品质;在MN或HN下,SD处理的产量、碾磨品质、外观品质和食味品质与WW的差异不显著或显著优于WW。说明土壤水分和氮素营养对水稻产量和品质的影响存在着明显的互作效应,结实期土壤水势为-25 kPa、粒肥的施氮量为45 kg/hm2,稻米的品质较优、产量最高。     

冬小麦籽粒形成与幼穗发育的关系研究

为了稳定提高小麦粒重,通过多年对郑引一号、百泉41等多个品种的连续观察和测定,研究了冬小麦籽粒形成与幼穗发育的关系.结果表明,幼穗发育进程是影响早期粒重的主导因素,特别是幼穗发育的中后期,其发育强度对早期粒重的影响更为明显.无论哪种类型的品种,在幼穗发育快,特别是护颖分化期以后幼穗发育强度大的年份,其早期粒重高.早期粒重是最终粒重的基础,早期粒重高的年份,最终粒重通常也比较高.在这些观察与分析的基础上,提出了容易形成早期高粒重的发育进程指标及其相应的植株形态指标.