水稻耐低磷基因型种质的筛选与鉴定

对二百余不同基因水稻品种（组合）进行士培和砂培,用多个对相指标和绝对指标进行系统聚类分析,获得了大粒稻、汕优６３、巨粒等等一批耐低磷基因型品种（组合）和新三百粒、沪占七、红二号等一批低磷敏感基因品种（组合）。试验表明,应用土培和砂培相结合的方法筛选耐低磷基因型品种（组合）是可行的,与耐低磷基因型相比,缺磷时敏感基因产量下降的主要原因是由于每株穗数和结实率下降所致。     

Genotypic Difference in the Responses of Seedling Growth and Cd Toxicity in Rice (Oryza sativa L.)

The experiment was carried out to study the genotypic difference in the responses of seed germination, growth and physiological characters of rice seedlings to Cd toxicity. The result showed that the germination was slightly stimulated under low Cd concentration (0.01-1.5 mM Cd), while severely depressed under higher Cd concentration (2.0 mM). Rice seedlings exposed to 0.01 mM Cd showed slight increases in plant height, root volume, biomass and chlorophyll concentration. These parameters were significantly reduced when Cd level in the medium was increased to 0.5 mM, and meanwhile corresponding increase in superoxide dismutase (SOD) and peroxidase (POD) activities, and MDA (malondialdehyde) content was observed. However, SOD and POD activities declined when plants were exposed to 1 mM Cd when compared with those under 0.5 mM Cd. Cadmium addition lowered Fe, Cu and Mn concentrations in roots and shoots. There was significant genotypic difference in the response of these parameters to Cd stress. Under Cd stress, Xiushui 110 had the least inhibition of growth and increase in MDA content, higher shoot Cd concentration, and greatest increase in POD and SOD activities, indicating its higher tolerance to Cd toxicity, while Bing 9914 had the greatest reduction of growth, and Zn, Cu, Fe, and Mn contents, but greatest increase in MDA content, and least increase in activities of antioxidative enzymes, indicating its sensitivity to Cd toxicity.     

低磷胁迫对不同水稻品种幼苗生长和磷效率的影响

采用砂培方法 ,研究了低磷胁迫对耐低磷水稻品种 (大粒稻、莲塘早 3号 )与低磷敏感水稻品种 (沪占七、新三百粒 )幼苗生长和磷效率的影响。低磷胁迫后 ,沪占七、新三百粒的叶面积、株高、生长量受抑制程度明显大于大粒稻和莲塘早 3号。耐低磷品种的磷营养效率主要表现在磷的吸收能力 ,而不是磷素分配和利用效率差异。     

Responses of Contrasting Rice （Oryza sativa L.） Genotypes to Salt Stress as Affected by Nutrient Concentrations

The study was conducted to investigate the effects of applying different concentrations of the macronutrients K+,Ca2+,and Mg2+on the responses of contrasting rice(Oryza sativa L.)genotypes under salt stress.A solution culture experiment was conducted in a phytotron at the International Rice Research Institute(IRRI),under controlled temperature and humidity and natural sunlight.When subjected to salt stress of 100 mmol L-1 using NaCl,the salt tolerant genotypes FLA78 and IR651,accumulated less Na+and maintained lower ratios of Na+/K+,Na+/Ca2+,and Na+/Mg2+than the sensitive genotypes IR29 and Azucena.These tolerant genotypes also had higher concentrations of K+in their shoots and greater root and shoot biomass and green leaf area.Tolerant genotypes also maintained much lower concentration of Na+and lower and more favorable ratios of Na+/K+,Na+/Ca2+,and Na+/Mg2+in their active and developing tissues.Salt tolerance and shoot and root growth of both tolerant and sensitive genotypes were enhanced considerably when higher concentrations of Ca2+and Mg2+were applied in culture solution.The concentration of Na+and the ratios of Na+/K+,Na+/Ca2+.and Na+/Mg2+ in shoots also declined significantly.The beneficial effects of higher calcium were greater than that of magnesium and application of higher concentration of K+seems to have minor effects.Responses to salinity in rice can therefore be considerably enhanced through proper nutrient management,by increasing the concentrations of nu～ient elements that have favorable effects such as Ca2+and Mg2+Calcium is particularly more effective than both magnesium and potassium,and can be applied at relatively larger quantities in salt affected soils.     

2个水稻黄叶突变体的遗传初步分析

从粳稻品种中花11的转基因植株后代中,获得了2份黄叶突变体（Y-347和Y-427）,经PCR等分析,表明这2个黄叶突变均与Ds转座子插入无关。通过突变体与正常中花11杂交和回交试验,证明这2个黄叶突变体均为单基因隐性突变。根据2个突变体间的杂交结果,初步表明,这2个突变体是由2个位点发生突变产生的。     

农杆菌介导水稻转化条件的优化

应用TAC（transformation-competition artificial chromosome)载体和pCAMBIA1300分别与农杆菌LBA4404组合转化水稻成熟胚愈伤组织，探索了农杆菌转化的有关因素。结果表明：共培养培养基上铺上1张滤纸有利于控制农杆菌的过度生长；粳稻品种转化率明显高于籼稻；干燥处理能有效杀死农杆菌，并有利于提高转化率，预再生可提高抗性愈伤组织的再生率而提高转化率。     

不同遗传体系基因效应对水稻籽粒碳氮代谢的影响

选用6个不同类型的水稻品种(系),按完全双列杂交设计(6×5)配成一套亲本、F1和F23个世代的遗传材料。采用包括种子、细胞质、母体植株三套遗传体系的种子性状遗传模型和统计分析方法,分析了稻米可溶性糖含量、全氮含量、糖氮比3个性状的遗传特点。遗传方差分析结果表明,可溶性糖含量和全氮含量两性状的表现同时受到种子、细胞质、母体植株三套遗传体系的控制,其中可溶性糖含量和主要受制于二倍体母体植株核基因的显性效应;全氮含量、糖氮比主要受制于种子核基因的显性效应。遗传率和选择响应分析结果表明,可溶性糖含量、糖氮比的遗传率较小,对其进行选择不易奏效;全氮含量以直接狭义遗传率为主,采用单粒选择易取得较好效果。     

水稻矮秆性状研究及矮源育种利用

矮秆水稻品种的选育和推广是20世纪水稻育种工作最主要的成就之一。本文综述了水稻矮秆性状的遗传、水稻植株矮化机理以及矮源的育种利用等方面的研究进展,同时分析了水稻矮源利用和矮化育种中存在的问题,展望了其发展前景。     

低铅污染条件下不同类型水稻品种对铅的响应

以35个水稻品种为材料,采用人工污染的方法,研究了不同类型品种对被污染土壤中铅(Pb)的吸收特性及Pb在不同器官的积累.结果表明:在低Pb污染处理(土壤中Pb浓度为149.1 mg/kg)下,不同类型水稻品种、不同器官中Pb的积累量有明显差异,稻谷和精米中均以常规籼稻的积累量最多,常规粳稻积累量最少,杂交稻介于两者之间.低Pb污染和对照条件下,土壤中的Pb较多地在茎叶中积累,而由茎叶向稻谷或精米中运输的比例很低.土壤受低浓度Pb污染时,水稻籽粒中Pb的积累量并未显著高于对照.筛选结果显示,南粳41、南粳40精米中Pb含量达到绿色食品标准;华粳3号等5个品种达到无公害大米标准.     

水稻基因组序列研究进展

水稻是世界上最重要的粮食作物之一,是禾本科植物的模式植物。综述了基于图位克隆的水稻基因组序列,基因组大小为389 Mb,包括37 544个非转座因子相关蛋白的基因。95%的基因组序列被精确测定,包括全部的常染色质、2个完整的着丝点及6条完整的染色体。基因组中串联重复序列占14%,平均每Mb为51个SSR。SwaI光学限制性(酶切)图谱的构建使图距缩短了11%,使基因组大小变为382.17 Mb。     

转bar基因水稻杂交后代的除草剂抗性遗传

通过回交将抗Basta除草剂的bar基因转育到其它品种 ,是获得新的抗除草剂转基因材料的一种简便有效的方法。通过对转bar基因水稻人工杂交与回交后代除草剂抗性的连续跟踪鉴定 ,研究了bar基因在水稻杂种后代的遗传表现。结果表明 ,bar基因在杂种的早期世代基本符合 1对显性基因的遗传规律 ,但在杂种的自交世代中普遍观察到bar基因的异常分离现象 ,即已经纯化稳定的抗性植株的后代重复出现抗性分离 ,其分离比例多为 1∶1,极少数为 2∶1,其原因有待进一步探明     

云南稻种主要性状多样性分布中心及其规律研究

以云南省地州和县为单位对６１２１份云南地方稻种及其优异种质６０多人性状进行多样性和密度分布规律研究表明：（１）云南是中国稻种最大的遗传和生态多样性中心及优异资源的富集地区,尤其是滇西南的临沧、西双版纳、德宏、思茅和滇东南的文山共５个地州１３个县构成了云南稻种多样性中心,其稻种的多样性与生态多样性和民族的多样性息息相关,并与哈尼族善制梯田栽培稻谷有一定联系。（２）临沧地区不仅是云南稻种最大的遗传多样     

Studies on the Mechanism of Single Basal Application of Controlled-Release Fertilizers for Increasing Yield of Rice （Oryza sativa L.）

This paper was to explore the mechanism of single basal application of controlled-release fertilizers for increasing yield of rice （Oryza sativa L.）. Pot trials and cylinder trials were carried out from 2002 to 2005 to study the influences of single basal application of 3 controlled-release fertilizers on the changes of soil available N, root development, senescence and lodging resistance at late growth stages. Results showed that at 30 days after fertilization, single basal application of controlled-release fertilizers coated with vegetal-substance （CRF1） and polymer materials （CRF3） increased soil available N to 12.0 and 147.9%, respectively, in comparison to split fertilization of rice-specific fertilizer （RSF1）. Treatments of the two CRFs obviously benefited the development of root system, resulting in greater rice root weights with extensive distribution and higher root activity. In addition, the two CRF treatments, in comparison to RSF1, enhanced chlorophyll consents of the flag leaves to 9.5 and 15.5%, and soluble protein up to 89.7 and 108.0% respectively. Application of the two CRFs also made the base of rice stems strong and large, declined the proportion of shoot and root, increased root depth index. Though relatively low K rate, single basal application of the CRF3 coated with NH4MgPO4 could also promote the development of root system, enhance root activity and some physiological functions of flag leaves. Based on these results, it was concluded that major mechanisms for increasing rice yield by single basal application of the CRFs should be attributed to grater soil available N supply, superior development of root systems, better nutrient absorption capacity, slower senescence and enhancement of lodging resistance at late stages.     

水稻茎秆抗倒伏研究

[目的]探讨水稻茎秆的性状与抗压强度的关系。[方法]运用石蜡切片技术对10个水稻品种茎秆(包括3个节间)的形态、解剖特征进行系统研究;运用电子万能材料试验机技术测出各品种的抗压强度;对特征数据与茎秆抗压强度进行相关性分析。[结果]相关性分析显示,茎的外径、横切面积与茎秆抗倒伏能力密切相关,可作为茎秆抗倒伏的重要参考因素。品种63两优636的外径和横切面积明显高于其他受测试品种,且3节间都具有较高的抗压强度,产量也高。[结论]63两优636可作为水稻超高产的栽培品种。     

保试达防除水稻田杂草稻研究

[目的]明确保试达防除稻田杂草稻的效果及安全性,为稻田杂草稻防除提供高效、安全的解决方案。[方法]开展以保试达为基础药剂对杂草稻防除效果的研究,通过选择常年杂草稻发生严重的中产稻田为试验地和保试达单用、与农思它混用等方法进行试验。[结果]保试达和农思它对杂草稻和直播稻田的主要杂草都有较好的防治效果。硝酸钾、保试达和农思它配套使用处理对产量有最终安全性。[结论]研究结果为水稻生产提供了参考。     

水稻短宽粒基因SWG1的图位克隆

【目的】水稻产量由单位面积有效穗数、每穗粒数和粒重3个因素构成,其中,粒重主要由水稻的籽粒形态决定。筛选和鉴定新的粒型突变材料和基因,可为产量性状的分子设计育种奠定基础。【方法】在籼稻保持系西大1B(XD1B)的甲基磺酸乙酯（EMS）诱变群体中鉴定到一个短宽粒突变体short and widen grain 1(swg1);分析籽粒形态和其他农艺性状,并对颖壳进行组织细胞学观察分析;运用BSA法进行基因定位;通过遗传互补试验确定候选基因;采用qRT-PCR分析该基因的表达模式及其他粒型相关基因和细胞发育基因的表达水平。【结果】农艺性状分析发现,与野生型相比,swg1突变体粒长显著降低,粒宽显著增加,表现出短宽粒的表型;进一步组织和细胞学分析,发现突变体颖壳纵向细胞变短是粒长变短的主要原因,而粒宽增加是由于颖壳横向细胞数目和细胞大小同时增加。遗传分析结果表明,该突变性状受隐性单基因控制,通过图位克隆与遗传互补验证,确定候选基因为LOC＿Os07g42410,编码一个植物特异转录因子。qRT-PCR分析发现该基因表达无明显的组织特异性,在茎、叶、幼穗中表达强烈。通过对已知粒型相关基因、细胞...     

盐胁迫对水稻幼根乙醇脱氢酶和乙醛脱氢酶基因表达的影响

以水稻(Oryza sativa)南粳44号为材料,研究不同浓度NaCl胁迫对水稻幼根中乙醇脱氢酶(ADH3)和乙醛脱氢酶(ALDH)基因表达的影响.结果表明,NaCl浓度和胁迫时间都对ADH3和ALDH的表达有影响.与对照相比,100 mmol/L NaCl胁迫后ADH3和ALDH的相对表达量下降或没有显著变化;而300、400 mmol/L NaCl胁迫12、192 h时ADH3和ALDH的相对表达量极显著高于对照,胁迫48 h时这两个基因的相对表达量则显著或极显著低于对照.     

Bulked Segregant Analysis to Detect QTL Related to Heat Tolerance in Rice （Oryza sativa L.） Using SSR Markers

The study was undertaken to assess the genetic effect of quantitative trait loci （QTLs） conferring heat tolerance at flowering stage in rice. A population consisting of 279 F2 individuals from the cross between 996, a heat tolerant cultivar and 4628, a heat-sensitive cultivar, was analyzed for their segregation pattern of the difference of seed set rate under optimal temperature condition and high temperature condition. The difference of seed set rate under optimal temperature condition and high temperature condition showed normal distribution, indicating the polygenic control over the trait. To identify main effect of QTL for heat tolerance, the parents were surveyed with 200 primer pairs of simple sequence repeats （SSR）. The parental survey revealed 30% polymorphism between parents. In order to detect the main QTL association with heat tolerance, a strategy of combining the DNA pooling from selected segregants and genotyping was adopted. The association of putative markers identified based on DNA pooling from selected segregants was established by single marker analysis （SMA）. The results of SMA revealed that SSR markers, RM3735 on chromosome 4 and RM3586 on chromosome 3 showed significant association with heat tolerance respectively, accounted for 17 and 3% of the total variation respectively. The heat tolerance during flowering stage in rice was controlled by multiple gene. The SSR markers, RM3735 on chromosome 4 and RM3586 on chromosome 3 showed significant association with heat tolerance respectively, accounted for 17 and 3% of the total variation respectively. The two genetic loci, especially for RM3735 on chromosome 4, can be used in marker-assistant-selected method in heat tolerance breeding in rice.     

旱作水稻冠层光合有效辐射和叶面积指数与产量的相关性分析

[目的]为了了解旱作水稻(Oryza sativa L.)冠层光合有效辐射(PAR)、叶面积指数(LAI)与其产量的相关性关系。[方法]利用SUNSCAN冠层分析仪,对正在进行产量比较试验的旱作水稻新品系的冠层PAR、LAI分别进行测量,并测定各品系的产量。[结果]当水田种植条件下冠层PAR处于223.53～262.23μmol/(m2.s),旱田种植条件下PAR处于119.62～185.74μmol/(m2.s)时,各品系产量均较高;PAR偏低的品系产量较低,但PAR太高的品系产量反而降低。对于大部分试验品系,随着LAI的不断提高,产量也在逐步提高。[结论]旱作水稻高产需要其冠层PAR处于一定的范围内,PAR太高或太低都不易达到高产的目标。LAI与产量呈正相关关系。