水稻实用光温敏核不育系培矮64S不育性稳定化研究

 在人工气候室的人控光温条件下，通过1997～1999年3年22.0～23.0℃的低温处理，对水稻实用光温敏核不育系培矮64S进行了育性稳定化研究。结果表明：1)在人工气候室的低温条件下，采用“株系(再)鉴定、(再)筛选单株”的方法，对稳定高世代光温敏核不育系培矮64S的不育性是可行的，并筛选出套袋自交结实率和花粉不育度两级水平均已稳定的3个株系9862、103-1和103-2，而且其不育起点温度已降至22.5℃，比原始株系降低了近1℃。2)现有高世代光温敏核不育系培矮64S仍然存在育性的不稳定性，表现在受低温影响后其后代不同株系间花粉不育度和套袋自交结实率存在明显差异，说明对现有高世代光温敏核不育系的育性提纯很有必要。     

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     

水稻高世代光温敏不育系低温下育性选择效果研究

1997—2000年,以两系杂交水稻生产上应用最广泛的籼型实用光温敏核不育系培矮64S及其后代选系为材料,藉人工气候室的人控低温条件,研究了在22—23℃的低温处理下对高世代光温敏不育系的育性实施选择的效果。结果表明,经不同次选择的1997—1999年各年度间育性差异明显,选择次数较多的年度其低温处理后育性波动期内花粉不育度极显著高于选择次数较少的年度,说明对育性实施选择的效果显著。进一步对同一谱系不同选择次数株系在低温处理后的育性波动期内花粉不育度进行比较,发现单株选择对育性的影响有2种情况：1)在育性未稳定的株系内实施选择是有效的,增加选择次数可以显著提高株系的不育度;2)在育性稳定后的株系内实施选择是无效的,增加选择次数并不能提高株系的不育度。因此,对高世代光温敏不育系的育性进一步实施选择的效果关键取决于其育性：是否已稳定。     

用人工冷水池鉴定水稻光温敏核不育系雄性不育起点温度的研究

用人工冷水池与人工气候箱分别对8个水稻光温敏核不育系在它们育志换温敏感期进行5d日均温23.5℃（22－25℃）的冷水与6d日均温23．5℃（19．5－26．0℃）的冷气处理。结果表明：株S－1、陆18S、96－5－2S、139S及康201S在两种低温处理条件下均表现不育，自交结实率与花粉可染率均为0；培矮64S在人工冷气处理条件下也表现不育，自交结实率与花粉可染率为0，但在人工冷水处理条件下表现轻度可育，自交结实率为0．05％，花粉可染率为5．0％；810S与179S在两种低温处理条件下均表现可育，自交结实率为3．7％－18．5％，花粉可染率为4．3％－41．0％，但人工冷水处理条件下的自交结实率与花粉可染率明显高于人工冷气处理条件下的自交结实率与花粉可染率。说明用人工冷水池鉴定水稻光温敏核不育系雄性不育的起点温度是可行的，而且鉴定的灵敏度比人工气候箱更高。根据人工冷水池与人工气候箱鉴定的结果可知：株S－1、陆18S、96－5－2S、139S及康201S的雄性不育起点温度小于23．5℃，培矮64S的雄性不育起点温度在23．5℃左右，而810S与179S的雄性不育起点温度大于23．5℃。     

花药培养对水稻温敏核不育系香125S不育性的遗传纯化效果初探

在人工低温（23.5℃）和自然条件下研究了香125S DH（Double haploid）群体的育性变化、异交特性和重要农艺性状。结果表明,在23.5℃的人工低温条件下,DH群体各株系育性不一致,有11个DH株系（占36.7%）花粉不育度在99.5%以上,其中5个株系（占16.7%）花粉不育度达100%,自交结实率为0,是不育性稳定、不育临界温度低的DH系。各DH系的株高、穗长、有效穗、每穗总粒数和异交结实率与对照香125S差异不显著,DH系保持了原品种的优良农艺性状。花药培养技术是对水稻光温敏核不育系的不育性进行遗传纯化的有效方法。     

光温敏核不育水稻育性稳定性研究Ⅳ.不育起点温度漂移规律

以培矮64S和安湘S等不育基因来源不同的5个水稻光温敏核不育系为材料，在人工气候室进行长日低温处理，考查各材料从核心种子至原种一代各世代平均花粉不育度，以探明不育起点温度漂移规律。结果表明：1）不育起点温度漂移普遍存在于不同不育基因来源的光温敏不育系中；2）不育基因来源不同的不育系起点温度漂移幅度和漂移频率均存在明显差异。对不同不育系不育起点温度漂移规律以及生产上对光温敏不育系的利用策略进行了讨论。     

优质籼型旱稻光温敏核不育系GHS不育性遗传研究

以光温敏核不育系GHS、安湘S、培矮64S及GHS的突变可育株GHF和15个普通品种为材料,以花粉育性为指标,研究了GHS不育性的遗传规律.结果表明:GHS的不育基因与安湘S、培矮64S的不育基因不等位,GHS是一个新的光温敏核不育材料;GHS的不育性遗传属孢子体不育类型,其不育性由1对隐性基因控制,与细胞质无关.     

籼型优质光温敏核不育系1892S的选育

1892S是安徽省农科院水稻研究所用培矮64S的变异单株选育的中籼光温敏核不育系,2004年8月通过安徽省技术鉴定。1892S不育期间败育彻底,不育性稳定,不育株率100%,花粉不育度和套袋自交不实率均为99.97%;不育起点温度较低(23.5℃),在合肥不育期30 d以上;开花习性好,异交结实率高达60%以上;对白叶枯病和稻瘟病的抗性分别为中抗和抗;米质优,达国标GB/T 17891-1999优质稻谷3级标准;所配组合杂种优势强,其中皖稻153(1892S/RH003)于2005年1月通过了安徽省品种审定。     

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.     

温敏型雄性核不育水稻新种粤光S的发现与育性鉴定

2000年晚季在杂交组合超级97/明七596的后代中,发现和鉴定了温敏核不育水稻种质光S.经分期播种试验,光S在广州6月初9月底抽穗均表现不育,雄性不育期达100d左右;经人工气候箱光温处理,其在23.5℃条件下不育性出现波动,≥24℃时自交结实率为0,其育性主要受环境温度控制.经等位性检测,光S的核不育基因不同于培矮64S.     

In vitro reproduction in the annual pasture legumes subterranean clover (Trifolium subterraneum L.) and French serradella (Ornithopus sativus Brot.)

Pasture legumes are important components of both mixed farming rotations and permanent pastures in temperate climates. Breeding of two widely sown pasture legumes, subterranean clover (Trifolium subterraneum L.) and French serradella (Ornithopus sativus Brot.), is constrained by the long generation cycle, typically enabling only one generation per year. We hypothesized manipulation of culture medium and conditions would enable the development of a laboratory‐based protocol for in vitro reproduction in subterranean clover and French serradella. In vitro flowering and viable seed set was induced from both species. For subterranean clover, the most effective treatment was culturing on modified MS medium with 1 μm kinetin and 0·1 m sucrose under a 100 μmol m^?2 s^?1 light intensity and continuous photoperiod. For French serradella, culture on a hormone‐free B5 medium with 5 mm NH₄Cl and 0·1 m sucrose under a 100 μmol m^?2 s^?1 light intensity and 20 h photoperiod was optimum. It is expected this technique will have application in accelerating generation turnover within breeding programs, for the study of factors influencing flowering in pasture legumes, and for the propagation of valuable yet enfeebled plants such as embryo‐rescued hybrids.     

Estimation of lucerne yield stability for enabling effective cultivar selection under rainfed conditions

Evaluation of crop and forage yield stability is of increasing relevance in the context of current and recent environmental changes but, in contrast to other field crops, there are no published systematic analyses among forage crops in Europe. A study of stability performance was conducted with 13 Czech cultivars of lucerne at four locations over a 2‐year period with the following aims: (a) to evaluate yield stability of varieties across different environments and (b) to calculate measurable benefits of variety selection in relation to the specific environment. The cultivar Vlasta was identified as the highest yielding cultivar (annual yield 16.0 t DM/ha), whereas the lowest yielding cv. Magda, Tereza and Oslava averaged around 14.9 t DM/ha. Effect of genotype × environment interaction (G × E) was two times higher than for genotype alone. Additive main effects and the multiplicative interaction (AMMI) model showed that the highest yielding cultivars may not be stable across environments. This study demonstrated further that significant yield improvement could be detected, even among a relatively homogenous group of domestic cultivars, and this was driven mainly by site productivity: the improvement was +10% in low‐yielding sites, compared with +3% in high‐yielding sites. Results highlight that advanced agronomy should also consider stability parameters such as AMMI stability value or superiority measures for forage crops in response to the challenges associated with climate change.     

稻文化的再思考3:稻与社稷——印度、泰国等东南亚、南亚主要国家

东南亚、南亚地区是世界上重要的稻米产区,稻米在民众饮食生活和国家社会政治中占有重要地位,民众生活中也保存了非常悠久和丰富的稻作文化习俗及稻谷起源神话传说。本文分析了水稻在东南亚、南亚主要国家印度、印度尼西亚、泰国、越南、菲律宾、孟加拉国、缅甸的作用、地位、生产、消费、文化等情况,并指出了印度、印度尼西亚稻文化的主要标志。     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Model of wheat yield response to application of diclofop-methyl to control ryegrass (Lolium rigidum)

A general model of crop yield response to herbicide application is proposed. The model includes three components: the effect of herbicide dosage on weed density, the effect of surviving weed density on crop yield and the effect of herbicide directly on the crop. The model is used to estimate the response of wheat yield to application of diclofop-methyl to control ryegrass (Lolium rigidum) in Australia. It is found that the competitiveness of ryegrass plants surviving treatment is reduced by the treatment and that the proportion of yield loss at a given ryegrass density is not independent of the absolute weed-free yield. The response function is used to calculate economic thresholds and optimal herbicide dosages.     

大豆对钼与氮、磷、钾的吸收分配动态及相互关系的初步研究

大豆植株中其叶片的钼、氮、磷含量均高于茎杆、叶柄、繁殖器官高于营养器官。钾在整个生育期中都保持较高的水平,只是叶片中的含量低于其它器官。种子中的钼、氮、磷、钾含量都较高。大豆吸收钼及氮、磷、钾的数量因品种及各生育阶段而有差异,吸收量以结荚至鼓粒期为最多,鼓粒期以后,安农75—59的植株中氮、磷、钾吸收量明显下降,唯有钼还在继续吸收,而安激一号对钼及氮、磷、钾仍在吸收。大豆对钼与氮、磷、钾的吸收呈极显著的直线相关,尤其是钼与氮相关最明显。安农75—59亩产189.5kg,需要N素16.05kg,P_2O_54.25kg,K_2O8.43kg,微量元素Mo357.32mg。安激一号亩产214.5kg.需要N素18.00kg、P_2O_55.01kg、K_2O8.85kg、微量元素Mo449.57mg。安激一号的种子除糖、脂肪含量较低外,而氮、磷、钾、钼、维生素C的含量均高于安农75 59。     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

基于颜色和形状的茶叶计算机识别研究

综合利用计算机视觉、图像处理技术,增加茶叶的形状参数,改进神经网络算法,实现了茶叶品质识别的自动化。研究中通过数码相机等直接得到茶叶图像,经过对图像格式进行转换和预处理,然后基于HSI模型提取的茶叶颜色特征参数和二值化后图像提取的茶叶形状特征参数,通过遗传神经网络,最后完成对茶叶的自动识别。实验结果表明此方法能取得更好的识别效果,计算机的检测结果与人工检测结果高度吻合。     

Blackgram fiber (Phaseolus mungo): Mechanism of hypoglycemic action

The effect of the administration of blackgram fiber (Phaseolusmungo) on the metabolism of carbohydrates was studied in rats fed 30%NDF (neutral detergent fiber) diet. The experimental group showed a significant increase in liverglycogen level and a significant decrease in blood glucose. Significantincreases in the activities of glycogen phosphorylase, hexokinase, fructose-1,6-diphosphatase, glucose-6-phosphate dehydrogenase and isocitratedehydrogenase were observed in the experimental group. The activities ofphosphoglucomutase and glucose-6-phosphatase were significantly lower inrats fed the fiber diet. The study showed that blackgram fiber exhibitssignificant hypoglycemic action in experimental animals.