不同基因型水稻抽穗后衰老进程的比较研究

本实验对汕优63、J85、老来青等三种不同基因型水稻品种衰老过程中的生理生化指标进行了分析。结果表明，随着叶片衰老进程，剑叶中的叶绿素含量逐渐下降，丙二醛含量逐渐上升，而根系活力在抽穗后一直呈下降趋势。进一步比较三种不同类型水稻叶片的衰老进程，发现：(1)在外界环境一致的情况下，三种水稻在这三个指标上变化明显不同，其中粳稻老来青抗衰老程度最高，而最易衰老的是杂交稻汕优63；(2)汕优63在抽穗后5～10d内衰老最为迅速；(3)根系活力的下降早于叶片中与衰老有关的指标变化。这表明在衰老过程中，根系的衰老先于叶片。     

水稻水作与旱作对抽穗后剑叶光合特性、衰老及根系活性的影响

对水稻水作与旱作栽培模式下水稻衰老和后期一些生理活性的影响进行了研究。结果表明,由于水分的影响,水稻旱作不同程度加速了水稻生理机能的衰退,使籽粒干物质积累受阻,粒重下降而减产。水稻水作不仅改善了水稻剑叶光合因子,提高了光合效率,而且剑叶呼吸速率下降缓慢,相对电导率上升缓慢,SOD酶活性较高,MDA含量低,表明剑叶后期衰老进程慢,促进籽粒增重,产量高。此外,旱作水稻生育末期根系干物质积累、活力高及代谢旺盛的优势对籽粒增重也是一种负向影响;而水稻水作开花-灌浆期根系活力高,生育末期根系生理活性迅速衰退,保证了籽粒的充实     

不同叶色水稻叶片的衰老及对光强的响应

以淡绿叶水稻近等基因系fgl及其正常叶色的轮回亲本浙辐 802为材料,比较了不同叶色水稻抽穗后叶片的衰老进程,并在水稻抽穗后施以不同强度的光照,研究水稻生育后期光照强度对不同叶色水稻叶片衰老的影响。在自然光强下,淡绿叶水稻fgl的衰老慢于轮回亲本浙辐 802,fgl的叶绿素、叶面积指数和净光合速率的下降速率均慢于浙辐 802,特别是在灌浆前期和后期;开花后浙辐 802的SOD活性下降和MDA含量的上升均快于fgl。15%的遮光处理有利于提高浙辐 802的气体交换特性和光合性能,提高SOD活性,降低MDA含量;而浅叶色的fgl的光合速率较稳定,受光强的影响较小。     

乌金绿在水稻上的减肥增效试验研究

针对水稻生产中化肥的施用过量、利用率不高的现象,本文应用具有改善根际生物多样性功能的生物质小分子有机碳肥乌金绿,在不减少和减少肥料施用量两种情况下探讨其对水稻减肥增效的作用。结果表明,不减肥施用乌金绿和减肥施用乌金绿,均能提高水稻根系活力和叶绿素含量,增加有效穗数;乌金绿不减肥处理比常规用肥处理增产7.8%,乌金绿减肥处理与常规用肥处理产量相当,可避免化学肥料的浪费和减缓农业面源污染。     

水稻叶片衰老研究进展

叶片的衰老是植物生长发育的最后阶段,是一种基因编码的程序性事件。但在农业生产上,水稻叶片的过早衰老已经成为制约水稻发展的重要因素,研究水稻叶片的早衰对水稻育种改良具有重要意义。本文综述了近年来国内外有关水稻叶片衰老研究结果,主要包括水稻叶片衰老的机理、特征、影响叶片衰老的因子、常用的水稻叶片衰老的生理生化指标等,同时介绍了近年来有关水稻叶片衰老遗传研究进展。     

杂交稻根系代谢活性与叶片衰老进程相关研究

用木村Ｂ营养液水培威优３５、威优４９和常规稻湘矮早９号，测定叶片和根系ＳＯＤ活性，可溶性蛋白质含量及叶片叶绿素含量的动态变化。结果表明：叶片ＳＯＤ活性、可溶性蛋白质含量分别在雌雄蕊原基形成期和抽穗期出现峰值，而根系ＳＯＤ活性分别在二次枝粳原基分化期、孕穗后期和乳熟期出现峰值。叶片ＳＯＤ活性，可溶性蛋白质含量、叶绿素含量的降解速率，从抽穗至乳熟期杂交稻大于常规稻，并与空秕率成显著正相关；而从乳熟期至完熟期，则常规稻大于杂交稻，并与粒重成极显著负相关。     

水稻植株在二化螟为害后的生理变化

研究了不同类型水稻品种在二化螟为害后植株体内的一些生理变化,包括叶绿素含量、根系活力和钾元素吸收能力。不同水稻品种在主茎受二化螟为害形成枯心后,分蘖的叶绿素含量均降低,但与健康植株相比无显著差异。常规杂交稻汕优63和超级杂交稻两优培九在主茎枯心过程中根系活力显著增强,而粳稻秀水11枯心后根系活力反而显著下降。采用86Rb标记示踪原子法研究了在二化螟为害后水稻根系对土壤中钾的吸收能力的变化,发现秀水11主茎枯心24 h和48 h后分蘖中铷的含量比健康植株分别降低了5.23%和47.5%,说明对钾的吸收能力下降,而汕优63和两优培九分蘖中铷的含量分别比健康植株增加了2.91%和14.36%、21.3%和15.9%,即对钾的吸收能力提高。     

垄作栽培对冬小麦根系活力和旗叶衰老的影响

为了明确垄作栽培条件下冬小麦根系活力与旗叶衰老的变化规律,采用垄作种植方式与传统平作栽培相比较的方法,研究了2种不同种植方式对2个小麦品种烟农19和济麦19根系活力及旗叶衰老的影响。结果表明,垄作栽培中由于小麦种植在垄顶上,0-60 cm土层根系干重较平作栽培增加12％以上,深层土壤(20-60 cm)根系活力得到极显著提高。在垄作栽培条件下,小麦生育后期旗叶叶绿素含量和光合速率较传统平作均有显著提高。开花15 d后,垄作栽培条件下的SOD、CAT、POD活性及可溶性蛋白质含量等较传统平作栽培均有显著提高,MDA含量显著降低。垄作栽培与传统平作栽培在同等节水条件下有利于提高小麦深层根系活力,延缓旗叶衰老。     

氟磺胺草醚毒害玉米的生理指标分析

通过生物测定及生物化学分析方法,对氟磺胺草醚毒害玉米的生理指标变化进行分析。结果表明,氟磺胺草醚胁迫明显抑制了玉米的根系活力、叶绿素含量及光合速率,导致丙二醛含量明显升高。玉米的受抑制程度随着氟磺胺草醚残留浓度的增加而增大,低浓度的氟磺胺草醚对玉米抑制作用较小,浓度超过0.2 mg/kg显著影响玉米生长,残留浓度0.8 mg/kg抑制程度最大。     

棉花叶片衰老的基因型差异

 以冀棉616、鲁棉研28和DP99B为材料,测定各品种主茎叶和果枝叶中的叶绿素含量、过氧化物酶（POD）活性和丙二醛（MDA）含量等衰老相关指标,比较研究了棉花叶片衰老的基因型差异。研究结果显示,与鲁棉研28和DP99B相比,冀棉616主茎叶和果枝叶生理功能期较长,大龄叶片叶绿素含量高、MDA含量低,显示冀棉616的叶片较其它2个品种抗衰老。     

两系籼型杂交水稻齐穗后光合作用和衰老特性的研究

对籼型两系与三系杂交水稻群体光合作用和衰老特性进行了比较,研究结果表明齐穗后剑叶叶绿素和可溶性蛋白质含量、超氧化物歧化酶活性、群体光合速率、脂质过氧化产物丙二醛含量、群体干物质生产量在组合间差异达极显著水平,两系和三系中各有指标值高低的组合;群体光合作用和衰老特性的差别主要在组合间,而不在两系和三系两种类型之间,两系杂交稻未有明显的优势。籼型两系杂交水稻的配组中应选配齐穗后叶片衰老慢、群体光合速率高的组合,提高抽穗至成熟期的物质生产量。     

Relationship Between Changes in Leaf Endogenous Hormone Contents and Senescence During Grain Filling Stage of a Rice Hybrid and its Parents

A major problem in hybrid rice production is the occurrence of leaf senescence during the grain filling stage that can result in reduction of yield. Changes in contents of several endogenous hormones are related to leaf senescence. The relationship between endogenous hormones and leaf senescence in the rice hybrid Tiyou 418 and its parents Tijin and C418, was undertaken for investigation. Indicators of leaf senescence, including superoxide dismutase (SOD) activity, malondialdehyde (MDA) accumulation and chlorophyll content, as well as the contents of abscisic acid (ABA), zeatin riboside (ZR), gibberellin (GA1/3) and auxin (IAA) in the leaves were determined. Different rates of leaf senescence were observed in the three materials. Senescence occurred earliest and fastest in Tijin, followed by Tiyou 418 and then C418. A similar trend was recorded in ABA, ZR, and IAA contents during the grain filling stage in the three materials. Changes in (GA1/3 ZR IAA)/ABA ratios were also similar, being quite stable during the early stage of leaf senescence, and decreasing markedly during the late stage. The ratio declined more dramatically in Tijin, in accordance with its faster leaf senescence. The results suggest that the ratio of (GA1/3 ZR IAA)/ABA regulates chlorophyll content, SOD activity, MDA content and membrane lipid peroxidation. It is postulated that endogenous hormones may play a role in the regulation of leaf senescence in a systematic way.     

Relationship Between Changes in Leaf Endogenous Hormone Contents and Senescence During Grain Filling Stage of a Rice Hybrid and its Parents

A major problem in hybrid rice production is the occurrence of leaf senescence during the grain filling stage that can result in reduction of yield. Changes in contents of several endogenous hormones are related to leaf senescence. The relationship between endogenous hormones and leaf senescence in the rice hybrid Tiyou 418 and its parents Tijin and C418, was undertaken for investigation. Indicators of leaf senescence, including superoxide dismutase (SOD) activity, malondialdehyde (MDA) accumulation and chlorophyll content, as well as the contents of abscisic acid (ABA), zeatin riboside (ZR), gibberellin (GA1/3) and auxin (IAA) in the leaves were determined. Different rates of leaf senescence were observed in the three materials. Senescence occurred earliest and fastest in Tijin, followed by Tiyou 418 and then C418. A similar trend was recorded in ABA, ZR, and IAA contents during the grain filling stage in the three materials. Changes in (GA1/3 ZR IAA)/ABA ratios were also similar, being quite stable during the early stage of leaf senescence, and decreasing markedly during the late stage. The ratio declined more dramatically in Tijin, in accordance with its faster leaf senescence. The results suggest that the ratio of (GA1/3 ZR IAA)/ABA regulates chlorophyll content, SOD activity, MDA content and membrane lipid peroxidation. It is postulated that endogenous hormones may play a role in the regulation of leaf senescence in a systematic way.     

灌水方式对杂交水稻衰老及生育后期一些生理活性的影响

 对长灌水、间歇灌和早断水等灌水方式对杂交水稻衰老和生育后期一些生理活性的影响进行了研究，以期有助于杂交水稻衰老的谢节及最佳灌水方案的建立。结果表明，灌水方式明显影响杂交水稻的衰老，早断水使植株开花后不同时期遭受水分胁迫，不同程度上加速植株生理机能的衰退，使籽粒干物质积累受阻，结实率下降而减产。断水的时间越早，减产越严重而间隙灌溉由于延缓根系衰老，增强叶片光合能力，延长灌浆时间，提高了结实率，从而提高增产效率，其最终产量比长灌水和早断水分别增7．4％ 和13．7～28．3％ 不同供水状况可能通过对根系中某些氨基酸合成的促进和另一些氨基酸合成的抑制而对上部的衰老进行调节。     

Correlation of Leaf and Root Senescence During Ripening in Dry Seeded and Transplanted Rice

Dry seeding is a resource-saving rice establishment method. With an equivalent yield, dry seeded flooded rice (DSR) has been considered as a replacement for traditional transplanted flooded rice (TFR). However, the differences in leaf and root senescence during grain filling between DSR and TFR were seldom identified. In this study, the root length, root tip number and leaf senescence of rice varieties Huanghuazhan and Yangliangyou 6 during ripening were compared between DSR and TFR. Results showed that top three leaves in DSR had the characteristics of relatively lower SPAD value, lower N content and premature leaf senescence. In addition, both the total root length and total root tip number of DSR were significantly lower than those of TFR. In conclusion, premature and quick leaf senescence was related with inadequate root length and root tip number during ripening, which might result from the deficiency of nitrogen supply in DSR. Techniques on improving leaf nitrogen status and delaying the leaf senescence during grain-filling in DSR should be developed in future researches.     

吉林水稻品种耐冷性研究

冷害胁迫是造成水稻减产的重要因素。为探讨不同水稻品种的抗冷性,以吉林省25个主栽品种为材料,测定分析了在冷害胁迫条件下这些品种的脯氨酸、丙二醛、叶绿素及可溶性糖含量的变化情况。结果表明,所有参试水稻品种在冷害胁迫下其游离氨基酸含量升高,丙二醛含量显著增加;吉粳515、通禾66及秋田小町脯氨酸积累较多;与常温条件下相比,吉粳809、吉宏9和通禾66的叶绿素含量冷害胁迫下变化不是很显著,生长较好,耐冷性较为突出;吉粳515 、吉农大538和吉农大853在冷害胁迫条件下积累了更多的可溶性糖,进而提高了抗逆性;吉香6、宏科88抗冷性较弱,在栽培过程中,应注意对低温冷害的防御。     

钙对延缓杂交水稻叶片衰老的作用机理

以叶绿素、蛋白质含量为衰老的生理指标，研究了不同ｐＨ、Ｃａ２＋对杂交水稻叶片衰老的作用。结果表明，不同ｐＨ影响叶绿素和蛋白质含量，最适ｐＨ为６．０；此条件下的Ｃａ２＋浓度为０．０１～２０．００ｍｍｏｌ／ｌ，低浓度的Ｃａ２＋提高叶片中叶绿素和蛋白质含量，提高超氧化物歧化酶（ＳＯＤ）、过氧化氢酶（ＣＡＴ）、过氧化物酶（ＰＯＤ）活性，降低丙二醛（ＭＤＡ）含量；随着Ｃａ２＋浓度升高，则作用减弱；最适浓度为０．１ｍｍｏｌ／ｌ。Ｃａ２＋能延缓杂交水稻叶片的衰老，主要原因是由于Ｃａ２＋能提高叶片中活性氧防御酶的活性，降低活性氧的伤害作用。     

印度梨形孢对水稻的促生作用及其机理的初探

印度梨形孢(Piriformospora indica)是一种能与植物建立互惠共生关系的根部内生真菌,能促进植物生长,增加作物产量。为了研究印度梨形孢对水稻生长发育的影响,将印度梨形孢与籼稻苗共培养后,分析印度梨形孢对水稻植株高度、生物量、分蘖数、抽穗期、穗粒性状、叶绿素含量、硝酸还原酶活性、根系活力以及生长相关调控基因表达水平的影响。结果显示,接种印度梨形孢的水稻株高、地上部干鲜质量、分蘖数、硝酸还原酶活性和根系活力显著高于对照;与对照相比,印度梨形孢定殖的水稻植株抽穗期提前4~6d;印度梨形孢处理第3、4周后,叶片叶绿素含量比对照分别增加了19.77%和17.89%。RT-PCR分析表明,印度梨形孢定殖的水稻植株叶片中生长素相关调控基因OsIAA13和YUCCA的上调表达,表达量分别为对照的1.49倍和1.30倍;负调控水稻生长的NRR基因表达量为对照的58%。印度梨形孢促进水稻地上部的生长与叶绿素含量、硝酸还原酶活性、根系活力和生长相关调控基因的表达有关,印度梨形孢可能通过提高光合速率、增强水稻对矿质营养的吸收与利用和诱导生长素的分泌,促进水稻地上部的生长。