两系法杂交稻两优培九结实率稳定性及其与温度的关系

分析了1999~2000年中国南方稻区19个区域试验点和5个生产试验点两优培九的结实率和产量。与汕优63相比,两优培九结实率要低4.3~7.5个百分点,但变异系数相近;产量水平及其变异系数则相近。在南京（32[sup]。[/sup]3′N, 118[sup]。[/sup]48′E）5月5~25日播种,两优培九在9月4日之前齐穗,结实率为75%~90%,产量在1 kg/m2以上;播种期推迟至6月14~15日,出穗期将延迟至9月17~21日,结实率比适宜播期的结实率低10~15个百分点。开花受精期5 d日均温平均值在13.7~28.5℃范围内,温度每增加1℃,受精率提高1.9%~10.7%。花粉育性与始花前5 d日均温平均值呈极显著的二次多项式相关。抽穗期适宜日均温（受精率≥90%）和安全日均温（受精率≥75%）分别为26.5℃和22.9℃。结果显示,北纬34[sup]。[/sup]以南地区为两优培九适宜种植区,宜将开花期安排在日均温为26~28℃的时期。     

除草剂苄嘧磺隆对稻田土壤微生物活性和生物化学特性的影响

在室内培养试验条件下, 研究了不同剂量苄嘧磺隆（0~750 g/hm[sup]2[/sup])对淹水稻田土壤中微生物活性和生物化学特性的影响。结果表明,所有处理中土壤微生物生物量(磷脂含量)随培养期延长而缓慢减少,与对照相比,土壤微生物生物量(磷脂含量)随苄嘧磺隆增加而有所减少。所有处理中异养型细菌（富营养菌和贫营养菌）随培养期延长持续减少,与对照相比土壤中异养型细菌随苄嘧磺隆剂量增加而快速减少,尤其是苄嘧磺隆剂量较大（375和750 g/hm[sup]2[/sup]）的土壤中异养型细菌显著减少。土壤电子运输系统/脱氢酶活度在第1周内随培养时间延长持续下降,之后随培养时间延长而增强。与对照相比,土壤电子运输系统活度也随除草剂苄嘧磺隆施用剂量的升高而下降。第1周内土壤酚含量随培养时间延长持续增加,之后随培养时间延长而减少。 与对照相比,土壤酚含量随苄嘧磺隆施用剂量的增加而快速增加,尤其是苄嘧磺隆剂量较大（375和750 g/hm[sup]2[/sup]）的土壤中酚含量显著增加。在所有处理中,土壤中蛋白质含量随培养时间的延长缓慢减少,但不显著。土壤蛋白质含量随除草剂苄嘧磺隆剂量增加而略微增加,但不显著。     

一个主栽粳稻品种的不同种植方式与稻纹枯病拮抗细菌的消长及种类的关系

 以晚粳品种丙96-42为试材对杭州临平镇条播、撒播和移栽方式下水稻纹枯病拮抗细菌的群体变化及种类进行了研究，从水稻不同生育期采集叶片、叶鞘和谷粒样本810份，获得细菌菌株7193个。结果显示，在每种种植方式下，稻株上的拮抗细菌数量都是叶鞘中最多，谷粒中最少。3种种植方式下水稻纹枯病拮抗细菌的群体数量基本上是随着稻株成熟而逐渐下降，在水稻6个生育期中，拮抗细菌出现的高峰因不同种植方式而有所差异。条播稻上拮抗细菌占细菌总量的比率从苗期到蜡熟期维持在3.6%～4.8%，各生育期之间无显著差异，但撒播和移栽稻上拮抗细菌所占的比率因不同生育期而有所不同。从539份纹枯病拮抗细菌中鉴定出8个属的14个种，不同种植方式与水稻纹枯病拮抗细菌的种类无明显差异。     

盐胁迫浓度和胁迫时的温度对水稻耐盐性的影响

 在水培条件下，用5种不同浓度的NaCl溶液对20个水稻品种的3~4叶期幼苗进行盐胁迫处理，10 d后考查不同品种单株盐害级别、苗高、茎叶干重和根系Na[sup]+[/sup]/K[sup]+[/sup]含量比等性状。结果表明，0.5%的NaCl胁迫下，品种间的盐害级别和根系Na[sup]+[/sup]/K[sup]+[/sup]含量比差异最大；0.8%的NaCl胁迫下，品种间的相对苗高和相对茎叶干重差异最大。其中韭菜青、农林72、80 85、洞庭晚籼和丁旭稻为强耐盐水稻品种；Pokkali、IR26、小白芒、勐旺谷、明恢63为耐盐或中度耐盐品种。进一步选择8个耐盐性不同的水稻品种，在3种温度条件下进行苗期耐盐性鉴定，发现在相对低温[昼/夜为(23±3)℃/(15±1)℃\]时，水稻生长缓慢，不同品种的盐害级别和根系Na[sup]+[/sup]/K[sup]+[/sup]含量比均较低；在温度较高[昼/夜为(36±1)℃/(26±2)℃\]时，水稻生长加快，不同品种的盐害级别和根系Na[sup]+[/sup]/K[sup]+[/sup]含量比均增高；只有在适温条件[昼/夜为(30±2)℃/(24±2)℃\]下，水稻生长较快，品种间的盐害级别和根系Na[sup]+[/sup]/K[sup]+[/sup]含量比差别最明显。提出在适温条件下，以0.5%或0.8%的NaCl浓度进行水稻品种耐盐性的筛选和耐盐特性的遗传研究比较合适。     

水陆稻杂交组合叶片相对含水量的遗传研究

以3个水陆稻组合(旱稻277/春江016、巴西陆稻/春江016、旱稻502/郑稻6号）的亲本、F[sub]1[/sub]、B1、B2和F[sub]2[/sub]为试验材料,在人工控制条件下经干旱协迫处理,研究叶片相对含水量的遗传规律。叶片相对含水量表现为数量性状遗传特征,主要受加性效应控制,同时还受到显性效应的影响,其广义遗传率和狭义遗传率均较高。还对栽培稻品种的抗旱性改良方法以及陆稻种质资源在水、陆杂交稻中的利用进行了探讨。     

玉米热带资源的改良

美国在玉米热带资源改良方面取得了重要进展。得到了产量超过B73Ht×Mo17Ht的一些双交组合、单交组合和一些配合力高的优良自交系，同时测定了许多群体的配合力。这些优良的组合、群体和自交系是： ①双交组合有(105.5×8101)×B73Ht/Mo17Ht，(105.5×304.54)×B73Ht/Mo17Ht，(105.5×155)×B73Ht/Mo17Ht，(105.5×155.504)×B73Ht/Mo17，(105.5×304.504)×B73Ht/Mo17Ht等13个。 ②单交组合有Tecpeno×B73Ht类型的16个组合。 ③群体有Bov582，Bov585，Gua110，San349，Gua597。 ④自交系有1408—3，1401—1.1411—1，1411—7，1424—3，1424—4，1425—3，1496—1，1497－1。     

药液量及施药方法对不同株型水稻生育后期主要病虫害防效的影响

 设计不同药液量、喷雾方法（细雾、粗雾）防治水稻后期发生的重要病虫害。结果表明,在药剂有效成分用量相同时,对于发生在稻株上部的穗颈瘟、穗腐病和稻纵卷叶螟,同一品种和相同药液量下,细雾喷雾防效最好,粗雾喷雾防效最差;第1次喷细雾第2次喷粗雾,或第1次喷粗雾第2次细雾防效相当。同一品种相同喷雾方法,以用药量675 L/hm2或750 L/hm2防效最好,其次是900 L/hm2、1200 L/hm2和450 L/hm2,最差的是225 L/hm2。对于发生在稻株中下部的纹枯病和稻飞虱,同一品种相同药液量时,2次粗雾喷雾防效最好,其次是第1次喷细雾第2次喷粗雾,再次是第1次喷粗雾第2次喷细雾,2次细雾喷雾防效最差。无论是发生在上部的病虫害,还是发生在中下部的病虫害,药液量和喷雾方法相同,对秀水09的防效均好于对甬优12。同一品种相同喷雾方法,以900 L/hm2药液量防效最好,其次是1200 L/hm2和750 L/hm2,药液量少于900 L/hm2时,防效随药液量减少而下降。225 L/hm2药液量且采用细雾喷雾,对纹枯病和稻飞虱的防效均低于50%,特别是对甬优12的防效更差。但在有效成分相同的情况下,并非药液量越多防效就越好。     

小麦纹枯病抗性QTL分析

小麦纹枯病是世界性的小麦重要病害之一,培育和使用抗病品种是减轻纹枯病危害最经济和有效的手段。为了挖掘更多的小麦纹枯病抗性QTL用于小麦标记辅助育种,本研究构建了CI12633和扬麦158重组自交系群体,采用二代测序方法开发SNP分子标记,并对群体中的94个家系进行基因型分析,构建遗传连锁图;采用牙签接种和病麦粒接种的方法鉴定重组自交系群体纹枯病抗性,进而对小麦纹枯病抗性QTL进行定位。结果显示,构建的遗传连锁图包含3 355个分子标记,遗传距离为2 510.66 cM,共有31个连锁群,均能分配到相应的染色体;在5A(2)、6A、1B、2B、3B、4B、5B、6B(2)、7B、1D、2D(2)、4D和7D染色体共发现16个与小麦纹枯病抗性相关的QTL,单个QTL可解释9.0%～26.8%的表型变异;除了7B染色体的QTL来源于感病品种扬麦158,其余QTL均来自抗病品种CI12633;3B、7D和5A(Chr5A_564101963)染色体的QTL与已有报道一致,其余均为新发现的QTL。发现的QTL和紧密连锁分子标记为今后小麦抗纹枯病分子标记辅助育种以及抗纹枯病基因的克隆提供帮助。     

小麦抗纹枯病和赤霉病QTL定位研究

为给小麦抗病育种中分子标记的辅助选择提供依据,利用苏麦3号/白免3号重组自交系群体,对小麦赤霉病、纹枯病抗性QTL进行分子定位,证实了苏麦3号3BS染色体上的主效QTL,获得了连锁更紧密的分子标记;在6B、2B、6A、5A、3B染色体上分别检测到抗纹枯病QTL,可分别解释纹枯病抗性表型变异的9%～13%.相关分子标记可进一步用于标记辅助选择育种.     

枯草芽胞杆菌在油菜根茎叶的定殖动态和生防作用研究

采用常规方法跟踪枯草芽胞杆菌Tu-100在缩影系统油菜根际的定殖情况。Tu-100在油菜不同根段部位的定殖密度从上到下呈现了逐渐递减的规律。随着接种后时间的延长而逐渐下降。在根段8cm以外的根区几乎检测不到接种菌。在油菜播种后3d,定殖密度可达最高水平（8.3×105 个/g）,然后急速下降,30d后保持相对稳定的较低水平（1.3×102 个/g）。 在油菜三片真叶时喷雾接种一次,20d后,在茎和叶上不能检测到所接种的Tu-100,并且抗菌核病的能力也逐渐减弱。     

用于生物防治水稻纹拮病的抗细菌的筛选

 分别从健康的水稻植株、感染纹枯病植株、根际土壤、秧田水和菌核上分离出能拮抗水稻纹枯病的假单胞菌属(Pseudomonas spp.)和芽胞杆菌属(Bacillus spp.)的细菌菌株，大多数菌株在室内试验中对菌丝生长有抑制作用，有的菌株在温室试验中起抑制病害和对植株有保护作用， 有的(1／49) 具有促进秧苗生长的作用。纹枯病的病斑相对长度与病害发生率密切相关(r²=0.33，P=0.01)， 与抑菌圈大小(r²=0.3)和离体叶片病斑大小(r²=0.12) 无相关，植株干重与病斑相对长度和发病率均无显著相关(r²=0或0.1)。     

水稻穗瘟离体接种技术研究

水稻品种叶瘟鉴定,先后已应用了喷雾、注射、钳叶、针刺、涂抹等多种接种方法,鉴定效果良好。但在自然状态下采用注射、喷雾、湿棉球包穗等接种方法鉴定穗瘟,还遇到品种间抽穗期不一致和接种条件难以控制的难题。因此,目前常以诱发叶瘟的抗性来评价品种抗瘟性。叶瘟和穗瘟抗性虽有较高的相关性,但也存在一定的差异,使叶瘟鉴定结果并不能完全反映穗瘟抗生。但品种抗性的评价以穗瘟抗性最为重要,因此,研究穗瘟抗性鉴定的简易技术十分必要。     

羧基化壳寡糖络合碘（CCOS-I）对水稻纹枯病菌的抑制作用及机理初讨

为明确羧基化壳寡糖络合碘（CCOS-I）对水稻纹枯病的防治作用，以 20%井冈霉素可湿性粉剂为对照药剂，测定 CCOS-I 对水稻纹枯病菌的室内抑菌效果和田间防效，以及对超氧化物歧化酶（superoxidedismutase，SOD）、叶片过氧化物酶（peroridase，POD）、多酚氧化酶（polyphenol oxidase，PPO）、苯丙氨酸解氨酶（phenylalanine ammonia-lyase，PAL）和 β-1,3-葡聚糖酶（β-1,3-glucanase）等相关防御酶活性的影响。结果表明：羧基化壳寡糖络合碘对该病菌抑制效果明显，经室内毒力测定，其 EC50 值 12.22 mg/L，明显高于对照药剂 20%井冈霉素粉剂。田间药效试验结果表明，在水稻第 3 次用药后 14 d，100 g/hm2 的羧基化壳寡糖络合碘防效达到 80.66%，与井冈霉素有效剂量 150 g/hm2 的效果相当，优于同剂量井冈霉素处理。CCOS-I 在试验剂量范围内对水稻纹枯病有很好的防治作用，且对水稻生长无任何药害现在发生，可以诱导水稻相关防御酶活性提高，适用于水稻纹枯病的防治，具有一定的开发推广价值。     

Efficacy of Bacillus subtilis MBI 600 Against Sheath Blight Caused by Rhizoctonia solani and on Growth and Yield of Rice

Rice sheath blight disease(ShB),caused by Rhizoctonia solani,gives rise to significant grain yield losses.The present study evaluated the efficacy of Integral?,the commercial liquid formulation of Bacillus subtilis strain MBI 600,against rice ShB and for plant growth promotion.In greenhouse studies,four log concentrations of Integral(from 2.2×106 to 2.2×109 cfu/mL) were used as seed treatment(ST).After 25 d,seedlings were dipped(SD) into Integral prior to transplanting.At 30 d after transplanting(DAT),leaf sheaths were inoculated with immature sclerotia of the pathogen.At 45 DAT,a foliar spray(FS) with Integral was applied to some treatments.The fungicide control was 50% carbendazim at 1.0 g/L,and a nontreated control was also included.Overall,there were 10 treatments,each with five replications.ShB severity was rated at 52 DAT,and seedling height and number of tillers per plant were rated at 60 DAT.In 2009,two field trials evaluated Integral at 2.2×108 and 2.2×109 cfu/mL.Integral was applied as ST,and seedlings were produced in a nursery bed.After 32 d,seedlings were treated with Integral as SD and transplanted into 10 m2 blocks.Foliar sprays were given at 45 and 60 DAT.There were seven treatments,each with eight replications arranged as a factorial randomized complete block design.At 20 DAT,the plots were broadcast inoculated with R.solani produced on rice grains.Seedling height before transplanting,ShB severity at 90 DAT,and grain yield at harvest were recorded.Integral at 2.2×109 cfu/mL provided significant increase of seedling heights over other treatments under greenhouse conditions.The Integral treatments of ST + SD + FS at 2.2×109 cfu/mL significantly suppressed ShB over other treatments.In field studies,Integral provided significant increase of seedling height in nursery,and number of tillers per plant,compared with the control.ShB severity was significantly suppressed with higher concentrations of Integral compared to lower concentrations.Grain yield were the highest at an Integral concentration of 2.2×109 cfu/mL.Overall,Integral significantly reduced ShB severity,enhanced seedling growth,number of tillers per plant and grain yield as ST + SD + FS at the concentration of 2.2×109 cfu/mL under the conditions evaluated.     

不同药剂不同施药次数防治水稻纹枯病田间药效试验

通过田间试验,比较分析了不同药剂对水稻纹枯病的防治效果。结果表明,25%嘧菌酯悬浮剂1 350 g/hm~2、24%噻呋酰胺悬浮剂345 g/hm~2、25%丙环唑乳油600 g/hm~2对水稻纹枯病的防效均在87%以上,43%戊唑醇悬浮剂的防效为74.38%;4种药剂的田间药效比生产上常用药剂井冈霉素的防效分别提高0.79倍、0.75倍、0.69倍、0.43倍,头季和再生季每hm~2综合增收6 499元、4 042元、2 051元、1 913元。从防治效果和经济效益来看,25%嘧菌酯悬浮剂、24%噻呋酰胺悬浮剂、25%丙环唑乳油均可以作为本地防治水稻纹枯病的主体药剂进行推广应用。     

稗草病原菌防御性接种防治稻瘟病研究初报

 用稗草病原菌互格交链孢菌、弯孢菌、禾长蠕孢菌稗草专化型和尖角突脐孢菌在实验室人工智能气候箱防御性接种感稻瘟病的水稻品种原丰早，预接种后1、2、3、5和7 d分别挑战接种强致病力的稻瘟病菌“中A1”和“中B1”小种。结果表明，与对照相比，稗草病原菌防御接种后，稻瘟病病斑数减少，病斑减少率在35.59%~80.00%，病情指数明显降低，防效显著提高，达53.08%~81.56%。稗草病原菌挑战接种后对水稻秧苗无明显副作用。     

解淀粉芽孢杆菌B9601-Y2提高玉米生长和产量的效应

采用促进植物生长的解淀粉芽孢杆菌B9601-Y2拌、浸玉米种子和浇灌土壤后均能显著提高玉米生长速度和生物量。3×101～3×105 cfu/mL浓度菌液浸泡玉米种子1 h,播种后5 d苗高比对照(清水)提高119.88%～168.85%;浸种2 h,3×104 cfu/mL和3×105 cfu/mL处理则有抑制作用。采用1.6×108、6.2×107、3.9×107 cfu/mL菌液浇灌土壤,播种后7 d苗重比对照增加20.75%、27.36%和33.96%。以3.9×107～1.6×108 cfu/mL浓度菌液拌种处理,15 d苗龄的植株重量比对照增加4.03%～29.35%,在收获期株高增加6.00%～16.29%,产量增加5.76%～11.81%。高浓度处理促生长效果不如中浓度处理。     

Rice varietal difference in sheath blight development and its association with yield loss at different levels of N fertilization

Variety and nitrogen (N) fertilizer input are the two main factors that influence the development of sheath blight (ShB) caused by Rhizoctonia solani in intensive and high-input rice (Oryza sativa L.) production systems. This study was conducted to determine the varietal difference in ShB development and its association with yield loss across N rates. Two indica inbred and two indica/indica F₁ hybrid varieties were grown under 0 and 90 kg N ha⁻¹ in 2003 wet season (WS) and under 0, 75, 145, and 215 kg N ha⁻¹ in 2004 dry season (DS). Inoculation was done in 3.2 m² in each experiment unit to achieve uniform disease development. Disease intensity was quantified by measuring relative lesion height (RLH) and ShB index (ShBI) of inoculated 10 hills at flowering and 14 days after flowering. Plant traits, grain yield, temperature, and relative humidity inside the canopy were also measured. Consistent and significant varietal differences in ShB intensity were observed across N rates in both WS and DS. Among the four varieties, IR72 and IR75217H had higher RLH and ShBI than PSBRc52 and IR68284H at all N rates. Sheath blight index at 14 days after flowering had the closest correlation with yield loss from ShB. Varieties with taller stature, fewer tillers, and lower leaf N concentration such as IR68284H generally had lower RLH and ShBI, and consequently lower yield loss from the disease. Disease intensity and yield loss from ShB increased with increasing N rates, but the magnitude of yield loss varied among varieties. This suggests that fertilizer N should be managed more precisely and differently for varieties with different plant type in order to reduce the disease development and maximize grain yield in the irrigated rice systems.     

转几丁质酶基因（RC24）水稻中大2号抗纹枯病特性研究

导入外源几丁质酶基因“RC24”的水稻中大2号接种纹枯病菌的结果表明,接种病菌后病斑扩展速率和田间病情指数小,表现为对水稻纹枯病高抗。组织病理学研究表明纹枯病菌能侵入中大2号,并引发纹枯病,入侵时间和症状出现的时间与非转基因感病对照没有显著差异,但病菌菌丝体消解现象出现早于对照,其抗病性主要表现为限制病菌扩展。以中大2号与非转基因水稻材料配制的杂交组合的抗病性表明,杂交组合的抗病性均高于非转基因亲本,但其抗病性也会因母本的不同而有所变化。     

Biocontrol of rice blast by the phenaminomethylacetic acid producer of Bacillus methylotrophicus strain BC79

Strain BC79, isolated from primeval forest soil in Qinling, Mountains, China, was identified as Bacillus methylotrophicus based on morphological, biochemical, physiological and chemotaxonomic analyses as well as phylogenetic 16S rDNA sequencing data. This strain was able to suppress mycelial growth and conidial germination of numerous plant pathogenic fungi in dual cultures on solid media. For exploring potential biocontrol activity, we assessed fermentation conditions for studying B. meth1ylotrophicus BC79. The active substance of BC79, phenaminomethylacetic acid, was extracted by TLC and HPLC, and identified as the strongest inhibitory substance described in B. methylotrophicus. Experiments in a greenhouse showed that application of BC79 culture filtrates 24 h before inoculation of Magnaporthe oryzae, the causal agent of rice blast, had 89.87% biocontrol efficiency. B. methylotrophicus BC79 colonized rice plant tissues and at 10 days after filtrate application, its population in leaves (1.65 × 10⁸ CFU/g) was much larger than in stems (6.78 × 10⁷ CFU/g) or roots (3.56 × 10⁷ CFU/g). Field trials indicated that BC79 culture filtrate (4000 g/667 m²) showed the highest efficiency for M. oryzae, with 84.8% biocontrol effect, followed by of 15% phenaminomethylacetic acid extract (75.5%) and 20% tricyclazole (76.1%). Seedling and post-transplant stages were the best periods to apply BC79 for control of rice blast. The B. methylotrophicus BC79 strain hence has enormous potential as an agricultural agent for biocontrol of rice blast.