水稻闭颖授粉QTL的初步定位分析

水稻闭颖授粉遗传位点的发掘旨在研究其闭颖授粉机制。本研究利用闭颖水稻品系RV2429为母本,开颖授粉水稻品系Koshihikari为父本杂交得到F1代,F1自交得到F2,以双亲本及F2为研究材料,对双亲本的粒型及花器官结构进行比较,推测出浆片体积增加较小是RV2429闭颖授粉的原因。统计F2群体的开花表型和基因型,通过QTL IciMapping 4.1软件分析,初步定位到4个与闭颖授粉相关的QTLs,qCL4.1(4.75%),LOD值为2.559 3、qCL6.1 (5.12%),LOD值为2.999 1、qCL11.1 (5.06%),LOD值为2.799 6和qCL12.1(4.77%),LOD值为3.052 1,分别在4、6、11、12染色体上。本研究结果明确了控制水稻闭颖授粉的新基因位置,为以后的精细定位提供了实验依据,为加快闭颖授粉的育种进程提供帮助,对抑制基因漂流具有重要意义。     

闭颖授粉水稻CL01的抗逆性及其相适应的生理特点

本文对开颖授粉水稻材料T168和闭颖授粉水稻材料CL01进行了比较研究. 发现在连续人工降雨和低温处理条件下, CL01的结实率受影响较小; 相反, T168的结实率随着处理天数的增加而迅速降低, 说明CL01的抗逆性较强. 通过对从开花前5天到开花当天的花药和花丝的长度、浆片的大小以及在开花过程中浆片的鲜重和干重的变化的研究, 揭     

低温库出库的杂交水稻种子发芽率变化的研究

通过对中优1号等几个杂交水稻组合种子从冷库出库后30 d内的发芽率变化情况研究表明:除个别组合外,绝大部分组合发芽率均有较大幅度的下降.发芽率下降幅度与组合特性有关,种子闭颖较差的博优组合发芽率下降幅度最大,其次是中优系列组合,种子闭颖较好的特优系列组合发芽率变化则不大.     

开颖、闭颖小麦浆片的显微观察

为了研究小麦开颖、闭颖授粉的原因,为探索小麦开颖、闭颖授粉机理奠定基础。此研究以开颖授粉小麦漯麦4号和闭颖授粉小麦花培3号为材料,在小麦抽穗期取浆片,用冷冻切片法观察两个品种浆片的厚度,并测量浆片的厚度,发现漯麦4号浆片的厚度是花培3号的1.67倍。对浆片进行整体透明处理,用微分干涉差显微镜观察浆片整体外形和浆片的中部细胞,对比高度和宽度,发现两者浆片在高度和宽度上无明显差异;同时对比浆片表面中部细胞的大小,发现两者浆片的中部细胞大小也无明显差异。     

低温库出库的杂交水稻种子发芽率变化研究

通过对中优1号等几个杂交水稻组合种子从冷库出库后30d内的发芽率变化情况研究表明：除个别组合外，绝大部分组合芽率有较大幅度的下降。芽率下降幅度与组合特性有关，种子闭颖较差的博优组合芽率下降幅度最大，其次是中优系列组合；种子闭颖较好的特优系列组合芽率变化则不大。     

高产优质杂交晚籼新组合K优金谷1号

母本K17A引自四川省农科院水稻高粱所,具有高柱头外露率、高柱头生活力、高开花累积率、低闭颖率的优良异交特性,苗期较耐寒,分蘖力中等,千粒重较大,配合力强.     

茉莉酸甲酯对小麦颖花开放的诱导效应及其受水杨酸的抑制

De Vries(1971)从杂交种子生产的角度, 综述了小麦开颖性能与授粉、 受精的关系。 Heslop-Harrison和Heslop-Harrison(1996)则从浆片膨大与花丝伸长的同步性论证了小麦开颖受精和闭颖受精的差异。 王忠等(1989)发现了CO2能促进水稻和小麦开颖的效应。 但他们都没有提及植物激素对小麦开颖的影响。 　　曾晓春和周燮(1999)考     

注意查治水稻中后期病虫害

<正>一、稻曲病该病也是水稻的主要病害之一,为花期侵染,病菌借气流传播,侵染正在扬花的水稻花器和幼颖,水稻扬花闭颖后,病菌一般不能再侵入,水稻扬花灌浆期开始见病症。幼穗形成至孕穗期如遇天气温暖多湿、日夜温差小的气侯条件,偏施氮肥,后期稻株"贪青",密穗型的品种皆有利发病。     

杂交稻种子颖壳脱勾现象的形成与防治

杂交水稻及其不育系种子存在着严重的颖壳脱勾现象,这是不育系的一种遗传特性。某些制种措施及不恰当的脱粒和干燥也会使之加剧;在储藏过程中,此类种子的生活力迅速衰退,严重影响了自然混合种子群体的发芽及幼苗生长。选育闭颖能力强的不育系,改进制种技术,加强选种,采用湿润浸种、旱育秧等措施可防止或减轻其危害。     

杂交稻制种人工辅助授粉工具选择与应用研究

杂交水稻制种人工辅助授粉，采用双型授粉竿定期定位定操作进行授粉，母本穗层的花粉分布密度较为均匀，提高了及时花粉与非及时花粉的有效利用率，异交结实率比现有人工辅助授粉有明显提高。     

Predictive study of the advantages of cleistogamy in oilseed rape in limiting unwanted gene flow

Summary The aim of this study was to evaluate the interest of beginning the selection process on a new genetic characteristic, cleistogamy, to manage gene flow in oilseed rape. The first step was to introduce this characteristic in an existing model of gene flow between oilseed rape populations in time and space, GeneSys-Rape. The second step was to evaluate the parameters of the model linked to this characteristic using field experimentations. Cleistogamous oilseed rape was shown to have an autogamy rate as high as 94% and to emit 10 times less pollen than an open-flowered oilseed rape in the same conditions. But the cleistogamous character was also shown to be unstable in the genotypes tested. The third step was to evaluate the interest of cleistogamy using simulations comparing several genotypes with or without cleistogamy in two different cropping systems. These simulations showed that an oilseed rape both dwarf and cleistogamous was interesting to limit gene escape and that a 99%-autogamous oilseed rape was interesting to limit both gene escape from and harvest contamination of the 99%-autogamous oilseed rape.     

Identification and mapping of a QTL for rachis internode length associated with cleistogamy in barley

General knowledge of the closed flowering trait, or cleistogamy, of barley is still limited. The relationship between cleistogamy and spike morphology characters was studied and linkage of cleistogamy genes with a highly significant quantitative trait locus (QTL) for rachis internode length on the long arm of chromosome 2H was detected. The mapping populations consisted of 129 doubled haploid lines of ‘Mikamo Golden’ × ‘Harrington’ and 150 F₂ plants of ‘Misato Golden’ × ‘Satsuki Nijo’. The phenotypic variance explained by this QTL accounted for 77.5% and 82.6% of the variance in rachis internode lengt, respectively, in these two populations. The peaks of the QTL coincided with the positions of the cleistogamy gene loci.     

Stability of the cleistogamous trait during the flowering period of oilseed rape

At the field scale, the co-existence of different farming production systems requires strategies to prevent gene flow between adjacent crops. Oilseed rape produces pollen dispersed by wind and insects and the risks of pollen mediated gene flow are significant for this crop. Cleistogamy, the trait of non-opening flowers, could be used to reduce pollen flow. Cleistogamous oilseed rape genotypes were obtained by INRA in France and were bred in order to improve the stability of this trait. In this paper, we examine the reliability of the cleistogamous trait for two inbred lines. The flower opening level was measured at different dates during the flowering period in six field experiments (three sites × 2 years). The results showed that some flowers were partially opened with rates varying from 0.5% to 33% principally depending on genotypes, trials (site and year) and recording dates. Given that other studies have shown that cleistogamy could reduce pollen dispersal, we consider that, even when partially unstable, cleistogamy could be beneficially used in combination with other means in a containment strategy.     

Agronomic traits and gene containment capability of cleistogamous rice lines with the superwoman1-cleistogamy mutation

Pollen-mediated transgene flow is a major concern for the production of genetically modified (GM) rice. Cleistogamy is a useful tool for preventing this form of gene flow. We previously identified the cleistogamous rice mutant superwoman1-cleistogamy (spw1-cls) and determined its molecular genetic mechanism. In the present study, we cultivated spw1-cls over five years to examine effects of cleistogamy on agronomic traits. Simultaneously, we cultivated cleistogamous backcross lines created by continuous backcrossing with “Yumeaoba” (a japonica cultivar) as the recurrent parent and by application of a DNA marker. In these experimental cultivations, spw1-cls and its backcross lines showed almost equal or slightly lower, but acceptable, agronomic traits compared with each control line. We also conducted natural crossing tests in paddy fields to assess the gene containment capability of spw1-cls. In a series of field experiments, there was no natural crossing between spw1-cls (pollen donor) and pollen recipient lines, but the wild-type donor and recipient lines were crossed. Thus, the cleistogamy of the spw1-cls mutation is able to inhibit natural crossing effectively, without significant loss of commercial benefits, such as yield. We conclude that spw1-cls cleistogamy is a practical tool for gene containment in GM rice cultivation.     

江西红壤旱地木薯农艺性状与产量的关系初步研究

为筛选出更适宜江西省种植的木薯高产品种,以19个品种（或品系）为材料,对不同品种间产量差异及其与农艺性状的关系进行研究。结果表明,5个品种的鲜薯产量高于37.5 t/hm2,6个品种的鲜薯产量介于30~37.5 t/hm2之间,4个品种的鲜薯产量介于22.5~30 t/hm2,其他4个品种的鲜薯产量低于22.5 t/hm2。19个木薯品种中有7个品种的鲜薯产量高于对照品种SC205,其中SC8和GR024-2的鲜薯产量和淀粉含量均表现较高。木薯的生物产量、收获指数、最粗薯粗与鲜薯产量呈极显著正相关,鲜薯干物率与鲜薯产量呈极显著负相关,而单株薯数、鲜薯淀粉含量、株高、茎粗、最长薯长与鲜薯产量相关不显著。     

低磷胁迫下水稻不同品种根系有机酸分泌的差异

以4个对低磷反应不同的典型水稻品种（系）为材料，对其在低磷胁迫下根系有机酸分泌这一根系生理特性进行了比较研究。结果表明，低磷胁迫能促使水稻根系分泌更多的有机酸，这在耐低磷品种中表现尤为明显。     

冬小麦田间水分反应特性产量评价指标研究

摘要：【目的】为全面有效地评价冬小麦品种对水分的反应特性。【方法】根据2007年和2008年不同小麦品种大田灌水试验的结果分析了抗旱系数(DC)、抗旱指数(DRI)、干旱产量指数(DYI)、丰水产量指数(WYI)、产量-水分高效利用指数(YWI)、水分适宜指数(WAI)和产量系数(YC)的适用性。【结果】DC反映品种的水分敏感性;DRI适合筛选旱地产量高且灌水增产不显著的品种;DYI较好的反映干旱条件下的产量,WYI能够反映不同品种的灌水效率差异,YWI适合筛选干旱条件和灌水条件下产量较高的种质。WAI适合参试品种间相对比较,但对同一品种适水性的评价效果因品种而异。产量系数(YC)适于组内筛选抗旱品种、高产品种和某灌水条件下水分高效型品种。【结论】初步提出多指标评价品种水分反应特性的方法和统一的分级标准。提出在合理选用对照种和明确水分鉴定条件的前提下,采用干旱产量指数修订值鉴定品种的抗旱性,用丰水产量指数修订值鉴定各水分条件下品种的水分高效性,用各水分条件下品种的平均产量相对值鉴定品种的高产性,采用阶段敏感指数鉴定不同生育期的水分敏感性,采用产量系数修订值鉴定品种的适水性。     

普通小麦名特优稀种质创新筛选研究

为适应贵州生态条件对小麦特早熟与高产的需要,在遗传研究的基础上,同时育成了一些在贵阳为特早熟、特大粒、特大穗的小麦新种质,并育成几个有希望为生产直接利用的特早熟、特大粒丰产新品种。特早熟新种质比早熟对照种早15～20天,特大粒新种千粒重64克,特大穗新种质每穗有29～32个小穗。实践证明,为稀特种质选育提供理论指导的遗传研究,应特别重视对超亲极端型个体的研究分析。特早熟育种的亲本选配,要重视个体生育阶段的互辅性。选育半冬性特早熟,是解决高产与早熟矛盾的有效途径。