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1.
中国钉螺螺壳的聚类分析   总被引:9,自引:2,他引:7  
对中国9省34个现场点的钉螺16项壳形指标进行了数值分类研究。主要成分分析结果壳体大小、壳形和壳厚为描述钉螺壳的主要特征。光壳螺组内,壳形特征较壳体大小和壳厚特征更重要,而肋壳螺组内三者的重要性基本相同。其中,壳顶角度为壳形的主要指标,第三螺层宽、壳高和壳缘胼胝长度为壳体大小的主要指标,唇嵴厚度为壳厚的主要指标。  相似文献   

2.
生赤壳科和丛赤壳科的中国新记录种   总被引:1,自引:0,他引:1  
张向民  庄文颖 《菌物系统》2003,22(4):525-530
本文报道了生赤壳科和丛赤壳科的中国新记录16个种,它们隶属于生赤壳属(Bionectria)、丽赤壳属(Calonectria)、赤壳属(Cosmospora)、血赤壳属(Haematonectria)、丛赤壳属(Nectria)和拟赤壳属(Nectriopsis),变更了一个种的名称。  相似文献   

3.
张向民  庄文颖 《菌物学报》2003,22(4):525-530
本文报道了生赤壳科和丛赤壳科的中国新记录16个种,它们隶属于生赤壳属 (Bionectria)、丽赤壳属 (Calonectria)、赤壳属 (Cosmospora)、血赤壳属 (Haematonectria)、丛赤壳属 (Nectria)和拟赤壳属 (Nectriopsis),变更了一个种的名称。  相似文献   

4.
研究以经过连续7代人工选育壳白长牡蛎品系为素材, 通过巢式设计, 成功构建了12个半同胞家系和29个全同胞家系, 同时以未经选育的个体子代为对照组, 评估了各家系和对照组幼体在不同日龄下的生长和存活差异。结果显示, 不同日龄, 壳白长牡蛎家系幼体生长和存活率均高于对照组, 壳高和存活率分别提高3.65%—14.58%和1.11%—19.26%; 生长和存活性状在不同壳白家系间差异显著(P<0.05), 其中G11、G15和G35家系在生长和存活率方面均有较大优势, 在19日龄, 与壳白家系平均值相比, 其壳高的累积生长量分别增加11.87%、17.03%和30.32%, 存活率分别提高38.35%、33.41%和51.07%; 与对照组相比, 其壳高的累积生长量分别增加34.09%、28.18%和49.31%, 存活率分别提高65.00%、59.11%和80.18%。同时对壳白长牡蛎幼体壳高和壳长的遗传参数进行了评估。壳白长牡蛎幼体壳高和壳长的遗传力变化范围分别为0.28—0.81、0.42—0.88, 均属于中高遗传力; 壳白长牡蛎幼体不同日龄壳高和壳长的遗传相关和表型相关均为正相关, 相关系数的范围分别为0.35—0.81、0.57—0.85。研究为培育生长性能优良和存活率高的壳白长牡蛎品系提供了基础资料。  相似文献   

5.
以杂交三倍体牡蛎、二倍体太平洋牡蛎、三倍体太平洋牡蛎为材料,比较其在池塘和水沟两种不同环境下养殖6个月后的壳高、壳长、壳宽、总重和死亡率。结果表明:水沟中养殖的三种单体牡蛎壳高、壳长、壳宽和总重均显著高于池塘中养殖的相同牡蛎(p0.05)。在同一养殖环境下,水沟组中杂交三倍体牡蛎的壳高、壳长、壳宽和总重则显著高于其余两种单体牡蛎(p0.05),而池塘组的三种单体牡蛎的壳高、壳长、壳宽和总重均无显著差异,且池塘组三种牡蛎的死亡率均高于相应的水沟组。因而,水沟比池塘环境更适合三种牡蛎的生长,而且杂交三倍体牡蛎比二倍体太平洋牡蛎、三倍体太平洋牡蛎生长更快。  相似文献   

6.
合成了壳寡糖和稀土离子La3+的配合物,利用红外光谱、紫外光谱和差热-热重手段对其结构和性质进行了表征。采用抑菌圈法考察了壳寡糖、壳寡糖-La对革兰氏阳性菌金黄色葡萄球菌和革兰氏阴性菌大肠杆菌的抑菌活性。此外,紫外光谱、荧光光谱和循环伏安曲线法研究壳寡糖-La与牛血清白蛋白(BSA)相互作用。结果表明壳寡糖、壳寡糖-La对两种细菌均具有较强的抑菌活性,且壳寡糖-La的抑菌活性强于壳寡糖;壳寡糖-La使BSA的内源荧光猝灭,猝灭机制为静态猝灭,并计算了室温下壳寡糖-La与BSA的结合常数和结合位点数分别为6.35×104L/mol和1.29。  相似文献   

7.
本文报告广东小光壳炱属和附丝壳属18个分类单位,其中小光壳炱属Asteridiella16个,杨桐树生小光壳炱Asterldlella adinandricola H.Hu、艾纳香生小光壳炱Asteridiella blumeicola H.Hu、黄杞树生小光壳炱Asteridiella engelhardtiicola H.Hu、泡花树生小光壳炱Asteridiella meliosmicola H.Hu和银鹊树生小光壳炱Asteridiella tapisciicola H.Hu为新种,11个我国新纪录种;附丝壳属Appendiculella 2个,嘉赐树生附丝壳Appendiculella caseariicola H.Hu和黄杞树生附丝壳Appendiculella engelhardtiicola H.Hu新种。  相似文献   

8.
本文报告广东小光壳炱属和附丝壳属18个分类单位,其中小光壳炱属Asteridiella16个,杨桐树生小光壳炱Asterldlella adinandricola H.Hu、艾纳香生小光壳炱Asteridiella blumeicola H.Hu、黄杞树生小光壳炱Asteridiella engelhardtiicola H.Hu、泡花树生小光壳炱Asteridiella meliosmicola H.Hu和银鹊树生小光壳炱Asteridiella tapisciicola H.Hu为新种,11个我国新纪录种;附丝壳属Appendiculella 2个,嘉赐树生附丝壳Appendiculella caseariicola H.Hu和黄杞树生附丝壳Appendiculella engelhardtiicola H.Hu新种。  相似文献   

9.
中街山列岛海域厚壳贻贝生物学特征及生长规律   总被引:2,自引:0,他引:2  
根据2013年4月—2014年2月厚壳贻贝Ⅰ龄个体跟踪调查和2013年8—12月Ⅱ龄个体取样调查数据,利用Taylor公式、线性函数和Von Bertalanffy生长方程对中街山列岛海域厚壳贻贝生物学特征及生长规律进行了分析。结果表明:雌雄样本间壳长、壳高、壳宽、体重、贝壳重和软组织湿重差异不显著;壳长与壳高、壳宽之间有极显著的线性正相关关系,壳长与体重、贝壳重、软组织湿重之间有极显著幂函数关系;壳长生长方程为Lt=87.48(1-e-0.348(t+0.913)),体重生长方程为Wt=79.51(1-e-0.348(t+0.913))3;8—10月是厚壳贻贝生长旺季,8月下旬为性成熟拐点,建议厚壳贻贝春季苗的最佳收获期为10月中旬。  相似文献   

10.
曾昭清  庄文颖 《菌物学报》2020,39(10):1981-1988
报道了采集于山东、河南、四川和云南的丛赤壳科4个中国新记录种:乌列沃光赤壳、假赤壳、瘤顶乳突赤壳和悬钩子乳突赤壳。对我国材料的宏观和微观特征进行了详细描述和图示,并与上述种的原始描述以及ITS和28S rDNA序列进行了比较。  相似文献   

11.
籽粒苋几个品种的光合强度测定   总被引:1,自引:0,他引:1  
经测定籽粒苋的光合强度显著高于大豆,从美国引进的几个品种的光合强度显著高于国内的品种。成分分析表明籽粒苋含蛋白质丰富,是有潜在开发价值的饲料作物。  相似文献   

12.
在不同土壤肥力条件下,研究了施氮量对小麦氮素吸收、转化及籽粒产量和蛋白质含量的影响。结果表明,增施氮肥可以提高小麦各生育阶段的吸氮强度,尤以生育后期提高的幅度为大认为是增施氮肥提高小麦籽粒产量和蛋白质含量的基础,增施氮肥虽提高了小麦植株的吸氮强度。吸氮量增加,但开花后营养器官氮素向籽粒中的转移率降低,增施氮肥不仅促进了小麦植株对肥料氮的吸收,而且也促进了对土壤氮的吸收,并讨论了在高、低土壤肥力条件下氮肥合理运筹的问题。  相似文献   

13.
Genetic dissection of grain yield in bread wheat. I. QTL analysis   总被引:1,自引:0,他引:1  
Grain yield forms one of the key economic drivers behind a successful wheat (Triticum aestivum L.) cropping enterprise and is consequently a major target for wheat breeding programmes. However, due to its complex nature, little is known regarding the genetic control of grain yield. A doubled-haploid population, comprising 182 individuals, produced from a cross between two cultivars ‘Trident’ and ‘Molineux’, was used to construct a linkage map based largely on microsatellite molecular makers. ‘Trident’ represents a lineage of wheat varieties from southern Australia that has achieved consistently high relative grain yield across a range of environments. In comparison, ‘Molineux’ would be rated as a variety with low to moderate grain yield. The doubled-haploid population was grown from 2002 to 2005 in replicated field experiments at a range of environments across the southern Australian wheat belt. In total, grain yield data were recorded for the population at 18 site-year combinations. Grain yield components were also measured at three of these environments. Many loci previously found to be involved in the control of plant height, rust resistance and ear-emergence were found to influence grain yield and grain yield components in this population. An additional nine QTL, apparently unrelated to these traits, were also associated with grain yield. A QTL associated with grain yield on chromosome 1B, with no significant relationship with plant height, ear-emergence or rust resistance, was detected (LOD ≥2) at eight of the 18 environments. The mean yield, across 18 environments, of individuals carrying the ‘Molineux’ allele at the 1B locus was 4.8% higher than the mean grain yield of those lines carrying the ‘Trident’ allele at this locus. Another QTL identified on chromosome 4D was also associated with overall gain yield at six of the 18 environments. Of the nine grain yield QTL not shown to be associated with plant height, phenology or rust resistance, two were located near QTL associated with grain yield components. A third QTL, associated with grain yield components at each of the environments used for testing, was located on chromosome 7D. However, this QTL was not associated with grain yield at any of the environments. The implications of these findings on marker-assisted selection for grain yield are discussed.  相似文献   

14.
In storage facilities one can find grain either in stored grain mass or in grain residues in the store corners or machinery. Although it is claimed that grain residues are serious pest reservoirs since they harbor numbers of stored product arthropods and are connected via continuous emigration with grain mass, the documentation for this is not convincing. Therefore in 78 selected grain stores, we simultaneously sampled the grain mass and residues in order to compare concurrent mite communities in these two different habitats. We found 30 species in about 614 000 individuals in residues and 23 species in about 20 000 individuals in grain mass. Canonical correspondence analysis (CCA) of transformed abundance data showed differences in the communities of mites in grain mass and residues: (i) species associated to grain residues (e.g. Tyrophagus longior, Tydeus interruptus, Acarus farris and Cheyletus eruditus) and (ii) species associated to both grain mass and grain residues (e.g. Tarsonemus granarius, Acarus siro, Tyrophagus putrescentiae, Lepidoglyphus destructor and Cheyletus malaccensis). Although the residue samples had more mites and higher species diversity than the stored grain mass, no correlation in mite abundance and species numbers between samples from grain residues and grain mass was found, thereby indicating low connectivity of these two habitats.  相似文献   

15.
AlA对冬小麦不同粒位籽粒灌浆影响的动态模拟及特征分析   总被引:1,自引:0,他引:1  
以百农矮抗58为材料,采用大田试验的方法,研究了在始穗期喷施不同浓度(10mg/L、30 mg、50 mg/L)的5-氨基乙酰戊酸(5-Aminolevulinic acid,ALA)对冬小麦不同粒位籽粒灌浆特性的影响.应用Richards方程对10~50 mg/L ALA处理下冬小麦3个粒位(第Ⅰ、Ⅱ、Ⅲ粒位)的籽粒灌浆过程进行了模拟.建立在Richards方程基础上的籽粒生长分析显示:与对照相比,10~50 mg/L ALA处理使第Ⅰ和第Ⅲ粒位的千粒重分别增加了1.3~2.4g、3.4~4.7,较对照差异显著,第Ⅱ粒位的粒重与对照差异不显著;10~50 mg/L ALA处理使冬小麦3个粒位籽粒的平均灌浆速率和最大灌浆速率增大,灌浆活跃持续期延长,到达最大灌浆速率的时间提前.阶段灌浆特征参数的比较表明,在籽粒灌浆的渐增期,10~50 mg/L ALA处理使冬小麦3个粒位籽粒的平均灌浆速率增加,灌浆持续期缩短;在籽粒灌浆的快增期,使3个粒位籽粒的平均灌浆速率增加,灌浆持续期延长.在籽粒灌浆的缓增期,使强势粒(第Ⅰ、第Ⅱ粒位)的平均灌浆速率减小,灌浆持续期延长,但使弱势粒(第Ⅲ粒位)的平均灌浆速率增加,灌浆持续期延长.表明在灌浆的前期和中期,10~50 mg/L ALA处理可促进各粒位籽粒提早启动灌浆,并提高其灌浆速率,在灌浆后期减弱了强势粒对弱势粒籽粒灌浆充实的优势,从而有利于弱势粒的灌浆充实.从总体上讲,10~50 mg/L ALA对弱势粒(第Ⅲ粒位)粒重的影响程度大于强势粒(第Ⅰ和第Ⅱ粒位),其中30 mg/L ALA促进籽粒增重的效果最明显.  相似文献   

16.
Topographic complexity is a key component of habitat, which has been linked to increased species richness in many ecological communities. It can be measured in various ways and it is unclear whether these different measurements are mutually comparable when they relate to plant species richness at different spatial scales. Using a densely sampled set of observations for Rhododendrons (406 species and 13,126 georeferenced records) as a test case, we calculated eight topographic complexity indices from a 250-m resolution digital elevation model and examined their correlations with Rhododendron species richness in China at seven spatial scales: grain sizes 0.05°, 0.1°, 0.25°, 0.5°, 1.0°, 1.5°, and 2.0°. Our results showed that the eight topographic complexity indices were moderately to highly correlated with each other, and the relations between each pair of indices decreased with increasing grain size. However, with an increase in grain size, there was a higher correlation between topographic complexity indices and Rhododendron species richness. At finer scales (i.e. grain size  1°), the standard deviation of elevation and range of elevation had significantly stronger correlations with Rhododendron species richness than other topographic complexity indices. Our findings indicate that different topographic complexity indices may have positive correlations with plant species richness. Moreover, the topographic complexity–species richness associations could be scale-dependent. In our case, the correlations between topographic complexity and Rhododendron species richness tended to be stronger at coarse-grained macro-habitat scales. We therefore suggest that topographic complexity index may serve as good proxy for studying the pattern of plant species richness at continental to global levels. However, choosing among topographic complexity indices must be undertaken with caution because these indices respond differently to grain sizes.  相似文献   

17.
Final grain dry weight, a component of yield in wheat, is dependent on the duration and the rate of grain filling. The purpose of the study was to compare the grain filling patterns between common wheat, (Triticum aestivum L.), and durum wheat, (Triticum turgidum L. var. durum), and investigate relationships among grain filling parameters, yield components and the yield itself. The most important variables in differentiating among grain filling curves were final grain dry weight (W) for common wheat genotypes and grain filling rate (R) for durum wheat genotypes; however, in all cases the sets of variables important in differentiating among grain filling curves were extended to either two or all three parameters. Furthermore, in one out of three environmental conditions and for both groups of genotypes, the most important parameter in the set was grain filling duration (T). It indicates significant impact of environmental conditions on dry matter accumulation and the mutual effect of grain filling duration and its rate on the final grain dry weight. The medium early anthesis date could be associated with further grain weight and yield improvements in wheat. Grain filling of earlier genotypes occurs in more temperate environments, which provides enough time for gradual grain fill and avoids the extremes of temperature and the stress of dry conditions.  相似文献   

18.
19.
密穗型水稻品种籽粒垩白性状改良研究   总被引:6,自引:2,他引:4  
采用籽粒长宽比较大、穗部着粒密的散穗型材料(EG23)改良粳稻密穗型品种的籽粒垩白性状.结果表明,经改良后得到的密穗型品系EA6,与原亲本浙粳20比较,其穗部长度缩短,每穗总粒数增加,着粒密度增大,而籽粒垩白特性得到明显的改善,表明在穗部长度和着粒结构未得到改良的情况下,调节籽粒长宽比对改善密穗型品种籽粒垩白性状具有可能性.穗部不同粒位籽粒垩白性状改良的效果不同,穗顶部和穗中部的改良效果明显优于穗基部.设计的4个不同杂交配组方式中,以反回交配组方式(浙粳20/ EG23//浙粳20)选育效果最好.EA6具有较好的农艺性状,既可作为优异种质资源利用,也可直接应用于生产.这一结果从育种实践上较好地协调了密穗型品种高产与优质的矛盾,对于培育既有密穗型的高产株型又有优良籽粒外观品质的水稻品种具有重要意义.  相似文献   

20.
High temperature reduces the grain quality of rice, a situation likely to become more frequent because of global warming. We studied the effects of high-temperature stress on grain quality of heat-tolerant cultivar ‘Genkitsukushi’ and heat-sensitive cultivar ‘Tsukushiroman’. When day/night temperatures were 31/26 °C from heading until maturity, the grain quality of ‘Genkitsukushi’ was rated at the first inspection grade (high quality), whereas ‘Tsukushiroman’ showed a remarkable increase in the percentage of white immature kernels (low quality). Nonstructural carbohydrate content in the stem of ‘Genkitsukushi’ the early maturation was significantly higher than in ‘Tsukushiroman’ and greatly decreased under high temperature. From 14 to 21 days after heading, the expression of the sucrose transporter gene, OsSUT1, was higher in the stem of ‘Genkitsukushi’ grown under high temperature than in ‘Tsukushiroman’. In addition, the expression of OsSUT1 in the grains of ‘Genkitsukushi’ was significantly higher than in ‘Tsukushiroman’ during the ripening period. These results indicate that sugar transport functions more effectively in ‘Genkitsukushi’ than in ‘Tsukushiroman’, and that the effectiveness of sugar transport contributes to maintaining high grain quality in ‘Genkitsukushi’ under high-temperature conditions.  相似文献   

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