拔节期霜冻胁迫对不同小麦品种源库特性的影响

为给小麦耐霜冻品种选育和抗霜冻丰产栽培提供理论依据,以半冬性偏冬性品种济麦22、半冬性品种舜麦1718和半冬性偏春性品种西农585为材料,在拔节期(幼穗药隔期)通过移动式人工霜冻箱模拟霜冻胁迫(-5～-3℃,5 h),研究霜冻胁迫对小麦源库特性的影响。结果表明,霜冻胁迫下,小麦幼穗冻伤率为31.4%～61.9%,穗粒数、穗数、千粒重和产量较对照分别降低8.4%～12.6%、3.2%～6.1%、0.8%～10.7%和19.7%～41.9%,耐霜冻能力表现为济麦22舜麦1718西农585。霜冻胁迫后,孕穗期和抽穗期各品种平均单茎叶面积分别减少15.5%和17.0%,叶面积指数分别减少19.5%和21.1%;霜冻胁迫初期光合速率下降28.5%～42.1%,孕穗后耐霜品种济麦22的光合速率提高3.6%～16.7%;叶片MDA含量显著提高;孕穗至成熟期生长率(CGR)比对照明显降低9.6%～22.0%,其中耐霜品种济麦22生长率降幅小,净同化率和粒叶比却分别提高26.9%和11.4%。小麦籽粒直径极显著降低,籽粒蛋白质含量提高1.3%～11.0%,面筋强度和沉降值稳定或提高。正常生长条件下小麦源库关系属库限制型,霜冻胁迫下属源库互作型。综上,霜冻胁迫打破了小麦原来源库平衡,显著降低了小麦的库容量和源强度,选择种植抗霜冻稳产品种或通过栽培措施调节高穗粒库容量和叶源活性,可减少霜冻导致的产量损失。     

水稻库源遗传生理学研究──Ⅰ 水稻不同时期主栽品种的库源特征研究

５０年代以来，水稻随着主栽品种的更新换代，产量库容和源强度不断扩增，促使稻谷产量登上新台阶。对不同历史时期主栽品种观测表明：库容增幅大于源强度增幅，从而库源比逐步提高。库客扩增主要靠每穗粒数增加，源强度提高主要靠叶面积扩大。株叶型的改进，确保了半矮秆常规稻和杂交稻的叶面积与群体生长速率得以同步增长。     

弱光胁迫对不同耐密型玉米茎秆抗倒伏能力及产量的影响

在大田条件下,研究耐密型玉米品种中单909和非耐密型玉米品种丹玉405穗期不同遮荫条件下(S0,自然光照;S1,遮荫44%;S2,遮荫66%)玉米茎秆抗倒伏能力与产量的关系。结果表明,穗期遮荫后,两种类型玉米品种株高和穗位高升高;茎基部茎节单位长度、干重、穿刺强度、压碎强度、折断力度、产量和穗粒数均随遮荫程度的增加而减小,且非耐密型玉米品种下降幅度大于耐密型玉米品种。随弱光胁迫程度的增加,非耐密型玉米品种倒伏率明显高于耐密型玉米品种,非耐密型玉米品种较耐密型玉米品种对弱光反应敏感,千粒重和结实率下降是导致非耐密型玉米品种产量大幅降低的重要原因。     

基于间套作弱光胁迫下作物源库协调与产量研究进展

光能在作物进行光合作用和籽粒产量形成中起着重要作用。随着我国种植结构和区划的调整,间套作种植模式在一些适宜地区得到广泛应用,增加了农田生产力。然而,间套作种植方式下,由于受高位作物荫蔽影响,低位作物在某一生长阶段常常处于弱光胁迫环境中。弱光胁迫不仅会引起作物生长发育不良,而且会制约作物产量潜力的提升。本文以间套作荫蔽环境下的大豆源库关系为例,综述了弱光胁迫调节作物源库器官生长发育的国内外研究现状;阐述了源库协调与作物产量之间的关系以及现有间套作作物产量研究概况与存在的不足;探讨了未来间套作种植下作物在源库关系与产量研究的发展方向。     

不同粒重类型玉米品种耐密性的群体库源特征研究

利用作物生长分析法,研究了不同粒型玉米品种产量、产量构成和群体库源特征等指标与种植密度的关系。结果表明,种植密度为30000～60000株/hm²,鲁单981(LD981)的单位面积实收穗数是决定群体子粒产量的限制因素;高于60000株/hm²,穗粒数与千粒重则是决定群体子粒产量的限制因素。泉兴2101(QX2101)群体子粒产量的限制因素是单位面积实收穗数。LD981的单株产量、群体产量与产量构成因素对种植密度的敏感度要高于QX2101,前者在较低密度时,易获得较高的群体库源比值与群体叶面积指数,产量潜力较高;后者则在较高密度时,易获得较高的群体库源比值与群体叶面积指数,产量潜力较高。群体库容量与源供应能力均是两种粒重类型玉米品种产量的限制因素,但群体库容量始终占主导作用。     

不同耐密性玉米品种光合特性对弱光响应的差异

以郑单958、东单90为试材,研究不同耐密性玉米品种光合特性对弱光胁迫响应的差异。结果表明,正常光照条件下郑单958光合性能优于东单90。郑单958在弱光胁迫后与其正常光照(对照)相比表观量子效率(AQY)增大,光合速率(Pn)、最大净光合速率(P max)、光补偿点(LCP)、光饱和点(LSP)均降低,表现出对弱光的光能利用效率明显高于对照,对强光利用效率较低。东单90在弱光胁迫后与其正常光照(对照)相比AQY降低,P max、LCP、LSP均升高,表现为对强光利用效率高,对弱光利用效率与对照基本相同。叶绿素荧光参数表明,郑单958弱光胁迫后PSⅡ光化学反应中心活性降低、高光强下光能利用效率降低主要是由于叶片光合活性下降;东单90弱光胁迫后对高光强的光利用效率升高的原因是叶片经弱光胁迫后减少了光合过程中的热耗散。     

盐碱胁迫对水稻源库与产量的影响

采用盆栽法,对2个盐碱敏感性不同的水稻品种89-45（耐盐碱）和吉农大10号（不耐盐碱）,在吉林省西部地区不同盐碱浓度的盐碱土中的表现进行了研究。盐碱胁迫导致叶面积系数变小,不耐盐碱品种较耐盐碱品种下降的趋势更明显; 盐碱胁迫降低了水稻有效分蘖数,最终导致产量下降,胁迫越大,产量越低。     

渍水胁迫对不同大豆品种叶片细胞超微结构的影响

本文是研究渍水胁迫对“宝交８３－５０２９”和“克８１１８”大豆品种叶片细胞超微结构影响的首次报道。随着渍水胁迫强度的增加,“宝交８３－５０２９”耐水性状逐渐显露,叶片由黄转绿。叶绿体,线粒体,过氧物酶体数量增加,饱满,活性增强。而“克８１１８”耐水性状较差,叶片萎蔫失绿。线粒体肿胀,内嵴消失,呈现空状,叶绿体膜被硕大的淀粉粒胀破。     

低磷胁迫对不同水稻品种叶片膜脂过氧化及保护酶

利用砂培方法,研究了耐低磷水稻品种（大粒稻、莲塘早3号）和低磷敏感水稻品种（沪占七、新三百粒）在低磷胁迫下,水稻叶片膜脂过氧化和保护酶活性的变化。研究结果表明,低磷胁迫使水稻叶片膜脂过氧化加剧,低磷敏感水稻品种的叶片膜脂过氧化程度高于耐低磷水稻品种;耐低磷品种叶片中SOD、CAT和POD活性在低磷胁迫期间相对稳定,而低磷敏感品种在低磷胁迫初期均有明显增加,尔后又快速下降,这表明保护酶的绝对活性与低磷胁迫无关,而变化趋势与低磷胁迫有关。     

弱光胁迫对不同基因型花生生理特性的影响

试验在田间以多粒型,珍珠豆型,龙生型,普通型和中间型五大类花生的种质为材料,齐苗后用透光率50%遮荫网遮荫40d,研究弱光胁迫对不同基因型花生叶绿素含量、光合特性及活性氧代谢的影响。结果表明,弱光胁迫下,花生叶绿素含量升高,光合速率、光系统Ⅱ最大光化学效率和细胞内保护酶活性降低。其中龙生型花生的叶绿素含量、光合特性及活性氧代谢各项指标受影响最小,普通型受影响最大。     

Effects of Weak Light on Starch Accumulation and Starch Synthesis Enzyme Activities in Rice at the Grain Filling Stage

Photosynthetic product in rice plant is transported to grains mainly in the form of sucrose. Sucrose in the grains eventually becomes starch through a series of enzymatic reactions [1-2]. The starch weight accounts for 90% of the brown rice [3-4], so the course of the rice grain filling is the biochemical process in which starch is mainly formed, and the factor of light is indispensable at the course. Much research has been conducted to study the influence of the light on the grain starch synt…     

灌浆结实期弱光对水稻籽粒淀粉积累及相关酶活性的影响

 选用IR72（籼稻）和日本晴（粳稻）为材料，在开花后进行遮光处理，对弱光条件下籽粒淀粉和直链淀粉含量的动态变化及相关酶的活性进行了研究。在弱光条件下，两品种籽粒的淀粉含量减少，直链淀粉含量下降，蔗糖含量降低，ADPG焦磷酸化酶活性的变化较小，可溶性淀粉合成酶和颗粒结合型淀粉合成酶活性减弱，可溶性淀粉分支酶Q酶和颗粒结合型淀粉分支酶活性增强，淀粉去分支酶活性因品种而异，IR72表现为减弱，日本晴则为增强。相关分析表明，遮光下蔗糖输入量的减少量和淀粉合成量的下降量呈显著正相关；ADPG焦磷酸化酶和淀粉分支酶活性与淀粉积累速率呈显著正相关。分析指出，遮光下淀粉合成酶活性的降低与淀粉合成量的下降有关，淀粉分支酶活性的升高是直链淀粉占淀粉总量的比率减少的重要原因。     

Effects of Low-Phosphorus Stress on Membrane Lipid Peroxidation and Protective Enzyme Activities in Leaves of Different Rice (Oryza sativa) Cultivars

Membrane lipid peroxidation and protective enzyme activity in leaves of low-phosphorus-tolerant rice cultivars Dalidso and Liantangzao 3, and low-phosphorus-sensitive cultivars Huzhanqi and Xinsanbaili were studied under lowphosphorus stress with sandy culture. Results indicated that low-phosphorus stress aggravated the membrane lipid peroxidation in rice leaves, and it was more severe in low-phosphorus-sensitive cultivars than that in low-phosphorus-tolerant cultivars. During the period of low-phosphorus stress, the activities of SOD, CAT and POD maintained relatively stable in low-phosphorustolerant cultivars, whereas those increased obviously at early stage and subsequently decreased rapidly in the low-phosphorus-sensitive cultivars, suggesting that the absolute activities of protective enzymes had no relation with the low-phosphorus stress, while the changing trend was reverse.     

不同时期干旱胁迫对水稻产量和生长特性的影响

为明确水稻生长过程中的水分敏感时期,探索水稻抵御干旱的栽培措施,以常规粳稻楚粳29号和云粳39号为材料,通过盆栽试验准确控制土壤水分(水势),研究不同时期干旱胁迫对水稻产量和生长特性的影响。结果表明,楚粳29号干旱胁迫处理较对照减产10.63%~47.60%,云粳39号干旱胁迫处理较对照减产6.19%~47.27%,减产程度依次为穗分化前期干旱胁迫(T2)﹥有效分蘖期干旱胁迫(T1)﹥穗分化后期干旱胁迫(T3)﹥孕穗期干旱胁迫(T4)。与对照相比,2个品种有效分蘖期干旱胁迫降低了有效穗数,穗分化前期干旱胁迫使每穗粒数明显减少,穗分化后期干旱胁迫使每穗实粒数减少和结实率明显降低,孕穗期干旱胁迫对结实率或千粒重有影响。     

盐胁迫对不同水稻品种光合特性和生理生化特性的影响

 用2个耐盐水稻品种和2个盐敏感型水稻品种为材料,研究盐胁迫对水稻植株生物量积累、光合特性等生理特性的影响。结果表明,在盐胁迫条件下,耐盐水稻品种和盐敏感型水稻品种地上和根系的干鲜质量均呈下降趋势,其中,以盐敏感型水稻品种的地上部鲜质量与根系干质量的下降最为显著。盐胁迫条件下,水稻叶片的净光合速率（Pn）、气孔导度（Gs）、蒸腾作用（Tr）和表观叶肉导度（AMC）均呈不同程度的下降趋势。其中,耐盐水稻品种Pn、Gs、Tr和Pn/Ci的下降均低于盐敏感型水稻品种。同时,耐盐品种水分利用效率（WUE）也高于盐敏感型品种。盐胁迫条件下,耐盐水稻品种和盐敏感型水稻品种的胞间二氧化碳浓度（Ci）变化并不明显,气孔限制百分率（Ls）均较低,品种间差异也不显著,而表观叶肉导度显著下降,由此推测盐胁迫条件下Pn的下降并非因为气孔的限制,而与RuBPCase活性的下降有关。盐胁迫条件下水稻叶片和根系的渗透性调节物质脯氨酸、总氨基酸和可溶性糖含量上升,其中以可溶性糖含量上升最为显著（P＜0.01）。盐胁迫下叶片保护酶SOD、POD和CAT活性增强,膜透性增强,丙二醛含量增加,同时,根系活力下降。     

Effects of Low-Phosphorus Stress on Membrane Lipid Peroxidation and Protective Enzyme Activities in Leaves of Different Rice （Oryza sativa） Cultivars

Membrane lipid peroxidation and protective enzyme activity in leaves of low-phosphorus-tolerant rice cultivars Dalidao and Liantangzao 3, and low-phosphorus-sensitive cultivars Huzhanqi and Xinsanbaili were studied under low phosphorus stress with sandy culture. Results indicated that low-phosphorus stress aggravated the membrane lipid peroxidation in rice leaves, and it was more severe in low-phosphorus-sensitive cultivars than that in low-phosphorus-tolerant cultivars. During the period of low-phosphorus stress, the activities of SOD, CAT and POD maintained relatively stable in low-phosphorus-tolerant cultivars, whereas those increased obviously at early stage and subsequently decreased rapidly in the low-phosphorus-sensitive cultivars, suggesting that the absolute activities of protective enzymes had no relation with the low-phosphorus stress, while the changing trend was reverse.     

Effects of Aerated Irrigation on Leaf Senescence at Late Growth Stage and Grain Yield of Rice

With the japonica inbred cultivar Xiushui 09,indica hybrid combinations Guodao 6 and Liangyoupeijiu as materials,field experiments were conducted in 2007 and 2008 to study the effects of aerated irrigation on leaf senescence at late growth stage and grain yield of rice.The dissolved oxygen concentration of aerated water evidently increased and decreased at a slow rate.The soil oxidation-reduction potential under aerated irrigation treatment was significantly higher than that of the CK,contributing to significant increases in effective panicles,seed setting rate and grain yield.In addition,the aerated irrigation improved root function,increased superoxide dismutase activity and decreased malondialdehyde content in flag leaves at post-flowering,which delayed leaf senescence process,prolonged leaf functional activity and led to enhanced grain filling.     

基于高光谱数据的晚籼稻品种剑叶SPAD值估测

本研究测定了长江中下游不同晚籼稻品种的剑叶SPAD值及反射光谱数据,分析了原始光谱及其变换数据与SPAD值的相关关系,建立了不同晚籼稻品种剑叶SPAD值估测模型,并采用平均偏差率对模型精度进行品种间验证.结果表明,水稻剑叶SPAD值与原始光谱的敏感波段位于710～720 nm之间,与一阶微分光谱的敏感波段为690～70...