短光敏核不育水稻D38S育性的感光性和感温性研究

以D38S为材料,对其育性转换与光周期、温度的关系进行了研究。结果表明:D38S育性主要受光照长度控制。表现为短日诱导花粉不育,长日诱导花粉可育,诱导不育的临界光照长度为13.25h。对光周期诱导敏感的时期为二次枝梗穗原基分化至花粉母细胞减数分裂期。在长日可育条件下,花粉母细胞减数分裂期的温度对花粉可育性有一定影响,在日均温20.9～30.0℃范围内,花粉可染率随温度上升而上升,当日均温超过31℃时,花粉的可染率随温度上升而下降。在人工12h短光照条件下,20,22,24,26和28℃5种温度处理的结实率都为0。     

籼型三系不育系育性与温、光的关系初探

通过分期播种试验,对生产上应用的水稻三系不育系天丰A、龙特浦A、Ⅱ-32A、金32A的花粉败育类型与始穗前15 d温、光条件的关系进行了探讨.结果表明,供试三系不育系的花粉败育程度在不同的温度下表现不同,天丰A的花粉可染率和自交结实率及Ⅱ-32A的花粉可染率均与始穗前15 d的日平均气温呈显著正相关,龙特浦A的花粉可染率和自交结实率均与始穗前15 d的日平均气温呈显著负相关,不育系育性与光长相关不显著.据初步观察,温度对不育系育性的影响时期为幼穗雌雄蕊分化期至减数分裂期.     

籼型光敏感核不育系的选育与利用研究——Ⅱ.不育系的育性转换特性

籼型光敏感核不育水稻在武昌自然光温条件下，具有两个育性转换临界期；其育性表现在受日照长度诱导的同时，温度也起着重要作用；温度对籼型光敏核不育水稻育性影响的敏感期在雌雄蕊原始体形成期至花粉母细胞减数分裂期；温度对花粉育性的影响没有明显的累加效应。     

W6154S育性变化与温度关系的研究

温度是诱导Ｗ６１５４Ｓ育性转换的主要因素。在长沙地区不育与可育转换的临界日平均温度为２６．５℃；温度诱导育性转换的敏感期为花粉母细胞减数分裂期。当日平均温度高于２６．５℃时，花粉发育走向败育，表现为不育；在２４℃以下时，多数花粉发育正常，表现为可育；在２４～２６．５℃之间时，部分花粉发育正常，部分花粉走向败育，表现为部分可育。     

水稻光温敏核不育系培矮64S低温下育性表达规律研究

藉人工气候室的人控光温条件 ,对两系杂交水稻不育系培矮 64S在 2 2 .0～ 2 3 .0℃的低温下的育性表达规律进行了连续 2年的跟踪研究。主要结果如下 :1) 2 3 .0℃的低温仅能导致培矮 64S花粉不育度的明显降低 ,而 2 2 .5℃和 2 2 .0℃的低温则不仅能导致花粉不育度的下降 ,而且还能诱导一定程度的自交结实 ;2 )培矮 64S的育性温度敏感终止期为幼穗分化第 6期 (花粉母细胞减数分裂期 ) ,育性温度最敏感期为幼穗分化第 4～ 5期 (雌雄蕊形成期至花粉母细胞形成期 ) ;3 )培矮 64S具有光敏性 ,其临界光长处于 13 5 0～ 13 .3 8h之间 ,光敏温度范围为 2 3～ 2 8℃ ;4 )对于农艺性状已经稳定的高世代培矮 64S而言 ,其控制育性表达的遗传基础尚不纯 ,表现在来源相同的不同株系间或同一株系内不同单株间在低温下育性表达存在显著的差异 ,且低温强度加大 ,这种差异就更为明显     

生态雄性不育小麦ES-10育性转换的温光效应分析

在长沙通过连续三年的分期播种试验,研究了生态雄性不育小麦ＥＳ－１０的育性转换的温光效应。结果表明：ＥＳ－１０为一个具有明显育性转换特征的生态雄性不育系,其雄性育性转换受光温两因子的作用,短日低温下表现不育,长日高温下表现可育,温度为其育性波动的主要影响因素,其对温度的敏感期为药隔期至花粉母细胞减数分裂期,为期约１０ｄ。     

水稻两用核不育系go543S育性转换的光温特性研究

以具有"低温不育、高温可育"育性转换特性的反温敏核不育水稻go543S为材料,对其育性转换光温特性和敏感期等进行了系统研究。结果表明,go543S的感光级别为Ⅱ级,感光性弱;而感温级别为Ⅲ级,感温性中等。自然条件和人工气候箱鉴定的结果均表明,go543S的育性转换主要受温度的控制,与光照长短无关,其育性转换临界温度值为29.5℃。温度诱导go543S育性转换的敏感期在雌雄蕊形成期至花粉母细胞减数分裂期,其中花粉母细胞形成期是最敏感时期。     

盛夏低温对光敏核不育水稻育性稳定性的影响

石明松发现湖北光敏感核不育水稻(HPGMR)具有长日诱导花粉不育,短日诱导花粉可育的育性转换特性;元生朝等探明了诱导HPGMR农垦58S育性转换的敏感期是在稻穗分化的第二次枝梗及颖花原基分化期至花粉母细胞形成期;贺浩华等研究表明;HPGMR的育性转换除受光照因子影响外,还有温度的作用,即光温组合效应,在一定的低温条件下,长口不能诱导花粉完全不育,但不同的HPGMR光周期诱导花粉完全不育所需温度不同。武汉在1989年盛夏期(指7月21日至8月10日的酷署期)出现了低温,这无疑对HPGMR的育性稳定性将产生影响,为此,我们对1989年在武昌观察的三个籼型、二个粳型HPGMR的育性变化进行了分析。     

水稻光敏核不育系GB028S光温反应研究

水稻光敏核不育系GB0 2 8S的育性表达受光长及温度影响 ,其温度敏感期在出穗前 1 5d左右 ,即在花粉母细胞形成致减数分裂期 ;不育起点温度为 2 2℃ ,可育临界高温大于 2 9℃。日均温度在 2 2～ 3 0℃之间 ,其育性主要受光长控制 ,可育临界光长为 1 3 5h ,光长转换期为 1 3 5～ 1 4 0h。GB0 2 8S在光长 1 2 0～ 1 4 0h条件下 ,结实率随温度升高而降低。在光长大于 1 4 5h ,温度高于2 2℃的条件下 ,花粉败育率和自交不实率均达到 99 9%以上 ,在辽宁的稳定不育期为 2 5～ 3 5d。     

亚种间杂交稻结实率稳定性的研究

以2个籼稻品种间杂交组合和4个亚种间杂交组合为供试材料，通过分期播种和人工气候室不同温度处理，研究了各杂交组合及其亲本的结实率稳定性。结果表明，亚种间杂交组合比品种间杂交组合和亲本在育性敏感期更易受温度的影响而造成结实率不稳定；父本与杂交组合的育性稳定性没有必然的联系；花粉败育是亚种间杂交组合遇低温结实率下降的主要原因。     

Effect of Temperature on Pollen Fertility in Inter-Subspecific Rice Hybrids

Seventeen rice varieties and hybrids of different types (indica, japonica, javanica, indica hybrid, japonica hybrid and inter-subspecific hybrid) were evaluated to determine the effect of temperature on pollen fertility in inter-subspecfic hybrids. The pollen fertility of inter-subspecific hybrids was greatly reduced when average daily temperature dropped to 22.0 - 23.0℃at meiosis stage, and the extent of pollen fertility reduction varied greatly with respect to different hybrids. However, the pollen fertility reduction of indica and japonica hybrids and conventional varieties was not obvious under the same regime of temperature conditions. When the average daily temperature dropped to 20℃, the pollen development of conventional varieties and hybrids was also affected. Correlation analysis revealed that there existed a positive correlation between pollen fertility and average daily temperature. A significant difference (P<0.01) was also found between the two correlation coefficients i.e. inter-subspecific hybrids and conventional varieties. Temperature at meiosis stage of pollen mother cell was a key factor in pollen developing, and the pollen fertility of inter-subspecific hybrids was more sensitive to low temperature than that of traditional variety.     

Breeding lines with neutral genes to improve fertility of intersubspecific hybrid rice

Since the sterility neutral allele S5n has been incorporated into indica or japonica varieties, many intersubspecific hybrids have been released commercially. These hybrids showed high heterosis, but some of them exhibited unstable seed setting rate under low temperature.When the hybrids flowered at low temperature, the fertility of female gamete was normal but the pollen showed sterile. To improve the stability of fertility, the effect of pollen sterility neutral gene was studied for intersubspecific hybrids.     

Agronomic Performance of F1 Hybrids of Rice (Oryza sativa L.) in Japonica-Indica Crosses

Summary

Generally F₁ hybrids from crosses between japonica and indica rice show variable degrees of sterility. Previous studies revealed that among the indica rice, the Aus type has sexual affinity with japonica cultivars giving higher fertility in F₁ hybrids. Therefore, we made an effort to obtain higher grain yield by producing F₁ hybrids between japonica and Aus-type indica. A field experiment was conducted to investigate the heterosis in these F₁ hybrids for dry matter accumulation, spikelet fertility, yield and yield attributes, to find cross combinations with higher grain yield, and examined the relationships of grain yield with some agronomic characters. F₁ hybrids flowered earlier than their parent cultivars. Heterosis for dry matter accumulation was positive at the panicle initiation stage, at heading and at maturity. The average heterosis for number of panicles, grain and straw yield per plant, number of spikelets per panicle and 1000-grain weight was positive. A few F₁ hybrids showed positive heterosis for number of filled grains per panicle, spikelet fertility and harvest index; but the average heterosis for these traits was negative. Among the yield components, a higher number of panicles per plant and higher number of spikelet per panicle contributed to higher grain yield in F₁ hybrids. A significant and positive relationship existed between spikelet fertility and grain yield per plant. The higher grain yield was attributed to higher dry matter production rather than higher harvest index in F₁ hybrids, although low spikelet fertility limited yield potential in some F₁ hybrids.     

Difference in Growth Characteristics,Utilization of Temperature and Illumination of Double- Cropping High Quality Late Rice in Different Ecological Regions of the Lower Reaches of the Yangtze River

【Objective】Under machine-transplanting conditions, four different types of late rice cultivars with high quality were used to investigate the differences of yield, growth characteristics, utilization of temperature and illumination. The results will lay a theoretical basis for the selection of double-cropping late rice varieties suitable for different ecological regions in the lower reaches of the Yangtze River.【Method】The yield, growth duration, dry matter accumulation, and utilization of temperature and illumination of double-cropping late rice were comparatively studied using four kinds of rice varieties as test materials namely indica conventional rice, indica hybrid rice, japonica conventional rice and Changyou japonica hybrid rice (20 varieties in total, selected between 2016 and 2017, all of which were high-quality rice in the lower reaches of the Yangtze River as double-cropping late rice). The experiment was carried out in two cities, Fuyang, Zhejiang Province (30.05º N, 119.95º E, 17.93 m above sea level) and Lujiang, Anhui Province (31.15º N, 117.16º E, 14 m above sea level).【Result】The yield of the four-types of late rice at high latitude was higher than that at low latitude. The yield of indica conventional rice, indica hybrid rice, japonica conventional rice, and Changyou japonica hybrid rice grown in Lujiang, Anhui Province was 11.1%, 12.9%, 6.6% and 12.4% higher than that in Fuyang, Zhejiang Province. When planted in the same places, Changyou japonica hybrid rice had the highest yield, and conventional indica rice had the lowest. The growth period was longer and dry matter accumulation was higher at high latitudes. When planted at high altitudes, the indica hybrid rice growth duration was the longest (10.4 d), and the increase in dry matter accumulation was the largest in conventional japonica rice (11.93% in full heading stage and 9.44% in mature stage). When planted in the same place, the dry matter accumulation was higher in hybrid rice than conventional rice. There was no significant difference in effective accumulated temperature between the filling stage and the whole growth duration of indica rice, but the sunshine hours, solar radiation, and its utilization rate were significantly higher at high latitudes. The effective accumulated temperature decreased significantly in the filling stage and the whole growth stage of japonica rice, but the change of accumulated sunshine hours was not obvious, while the accumulated solar radiation increased significantly at high latitudes. These were consistent with the changing trend of the utilization rate of the temperature and light resources. When planted at the same latitude, the growth period, dry matter accumulation, temperature and light resource utilization rate of japonica rice were higher than those of indica rice.【Conclusion】Late indica rice could make full use of temperature and light resources in order to improve its yield when planted in Lujiang, Anhui Province, but the difference of the utilization efficiency in the temperature and light resources of late japonica rice was not obvious. The yield of late japonica rice in Lujiang, Anhui Province increased because of the extension of the growth duration and the increase of dry matter accumulation.     

Correlation and Regressive Model Between Spikelet Fertilized Rate and Temperature in Inter-Subspecific Hybrid Rice

To study the sensitivity of inter-subspecific hybrid rice to climatic conditions, the spikelet fertilized rate (SFR) of four types of rice including indica-japonica hybrid, intermediate hybrid, indica and japonica were analyzed during 2000-2004. The inter-subspecific hybrids showed lower SFR, and much higher fluctuation under various climatic conditions than indica and japonica rice, showing the inter-subspecific hybrids were sensitive to ecological conditions. Among 12 climatic factors, the key factor affecting rice SFR was temperature, with the most significant factor being the average temperature of the seven days around panicle flowering (T7). A regressive equation of SFR-temperature by T7, and a comprehensive synthetic model by four important temperature indices were put forward. The optimum temperature for inter-subspecific hybrids was estimated to be 26.1-26.6℃, and lower limit of safe temperature to be 22.5-23.3℃ for panicle flowering, showing higher by averagely 0.5℃ and 1.7℃, respectively, to be compared with indica and japonica rice. This suggested that inter-subspecific hybrids require proper climatic conditions. During panicle flowering, the suitable daily average temperature was 23.3-29.0℃, with the fittest one at 26.1-26.6℃. For an application example, optimum heading season for inter-subspecific hybrids in key rice growing areas in China was as same as common pure lines, while inferior limit for safe date of heading was about a ten-day period earlier than those of common pure lines.     

两系杂交稻杂种低温下育性稳定性的初步研究

考察了水稻常规品种及两系杂交稻在低温影响后的花粉育性变化。结果表明：ａ）低温是影响水稻常规品种育性稳定性的重要生态,且受低温影响后不同品种表现出育性稳定性的明显差异;ｂ）在常温下杂种Ｆ１均能基本恢复正常可育,但在低温下Ｆ１的花粉育性都有所下降,且下降幅度在组合间差异明显;ｃ）Ｆ１的育性的稳定性与父本对低温的敏感程度有关;ｄ）母本对Ｆ１的育性稳定性也有重要影响。     

水稻粳型亲籼系亲和性的测定

通过研究建立了粳型亲籼系的检测方法和鉴定标准,以6个籼型和6个粳型品种作为亲和性测验种,凡与籼型测验种杂交F1的平均花粉育性达85%以上,且平均小穗育性达80%以上者,为亲籼系。利用测验种对10个待测粳型亲籼系的亲和性进行了测定,结果表明, G2416-3、G2417-2-1、G2605和G3004-4与籼型测验种的亲和性高,达到或基本达到亲籼性的标准,其中G2416-3和G2417-2-1与粳型测验种的亲和性低,为特异亲籼系,G2605和G3004-4与粳型测验种的亲和性高,为广亲和系。     

中熟类型甬优籼粳杂交稻组合产量优势形成及其形态生理特征

以中熟类型甬优籼粳杂交稻组合甬优2640、甬优1640为材料,常规粳稻镇稻11、武运粳30和杂交籼稻丰两优香1号、新两优6380为对照,比较各类型品种在干物质积累、穗部特征、叶片形态及茎秆特性上的差异。结果表明,甬优籼粳杂交稻两年平均产量为11.3 t/hm~2(11.1、11.4 t/hm~2),较常规粳稻和杂交籼稻分别高6.6%和13.0%;产量构成上,甬优籼粳杂交稻的每穗粒数和群体颖花量显著高于对照,有效穗数、结实率和千粒重低于对照;甬优籼粳杂交稻抽穗期、成熟期的干物质量及抽穗至成熟期的干物质积累量依次为13.4 t/hm2、21.6 t/hm~2、6.9 t/hm~2,均显著高于对照;穗部特征上,甬优籼粳杂交稻的单穗质量和着粒密度高于对照,穗长略低于杂交籼稻,近80%的籽粒集中于中上部,而常规粳稻75%的籽粒集中于中下部,杂交籼稻籽粒分布相对匀称;甬优籼粳杂交稻上3叶的叶宽和卷曲率高于对照,叶长和叶基角处于对照之间(以杂交籼稻最大),披垂度最低,上部1、3叶差异显著;株高、穗高、秆长及穗下节间占秆长的比例以杂交籼稻甬优籼粳杂交稻常规粳稻;成熟期单茎茎干质量、单茎鞘干质量及基部节间单位长度干质量以甬优籼粳杂交稻最高。中熟类型甬优籼粳杂交稻组合产量优势特征为足穗基础上,主攻大穗,并保持较高的结实率和千粒重;形态生理特征表现为籽粒集中于中上部,上3叶大小适宜,叶片内卷且直立,株高及穗下节间占秆长的比例适中,成熟期茎秆充实度好。     

籼粳稻之间的亲和性及其杂种优势

 发现粳稻品种秀水117和籼稻品种IR58分别表现亚种间杂交的亲和性。秀水117与IR58、二九丰的杂种一代结实率分别为85.9%和88.4%;IR58与T8340及粳型不育系双百A、农六209A和六千辛A的杂种一代结实率分别为81.1%、76.5%、74.5%和67.0%”秀水117/IR58”的F_1在株高、穗长、每穗粒数和单株稻谷产量等性状上均存在很强的正向超亲优势。该组合的亲和性在F_2及回交世代中仍可表现。试验结果表明,在籼、粳稻内各存在着亚种间杂交的亲和性材料,但其亲和性的表现范围可以不同。讨论了籼粳稻亚种间杂种优势利用的一些问题。     

叶枕距标记法研究低温对粳型光温敏核不育系育性转换的影响

用日均温20℃低温处理3个采用剑叶叶枕距标记幼穗发育时期的粳型光温敏核不育系G317S、G321S和G326S,研究低温对不同发育时期粳型光温敏核不育系育性的影响.结果表明:用20℃低温处理3d,3个粳型光温敏核不育系花粉不育度明显降低,平均自交结实率为66.41％;3个粳型光温敏核不育系育性敏感期所对应的剑叶叶枕距为-4 ～4 cm,而剑叶叶枕距＜-4 cm或＞4 cm时,各不育系育性稳定;剑叶叶枕距为-4～ -2 cm和2～4 cm时各不育系不同穗位颖花的花粉不育度比较接近,而剑叶叶枕距为-2～2 cm时,各不育系不同穗位颖花的花粉不育度表现为穗上部＜穗中部＜穗下部.