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采用试验观测的方法,对钢板仓仓储小麦分别进行不通风、两阶段和三阶段降温通风研究和分析。研究发现,相对于秋季两阶段通风而言,夏季增加一个通风阶段更有利于提高降温效果。在为期两年的试验中,在夏季合适的气温条件下,用较小的通风量进行降温通风,小麦有足够的时间与温度低于24℃的空气接触达到冷却的目的。然而,由于夜间空气温度低、湿度大的特点导致粮食最终温度高于24℃,同时由于送风湿度大的原因,粮食的水分也会相应增大。  相似文献   
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The male sterility system in hybrid seed production can eliminate the cost of emasculation and ensure seed hybridity through avoidance of self pollination. GMS and CMS are two types of male sterility system that currently employed in pepper breeding. Conversion from GMS to CMS will increase the male sterility proportion of female parent from 50 to 100%. In this study, segregation analysis of four male sterile mutants consisting of one CMS mutant (CA1) and three GMS mutants (GA1, GA3 and GA4) showed that each had single recessive gene inheritance. A modified complementation test was performed by replacing male sterile mutants with their maintainer line as male parent. The nuclear restorer gene for CMS was independent of all nuclear restorer genes for GMS and all nuclear restorer genes for GMS were independent each other. Further observation on CMS and GMS male sterility loci revealed that GA1 and GA3 had mutated in both nuclear restorer genes for CMS and GMS, while CA1 and GA4 each carried mutation in single male sterility system of nuclear restorer gene for CMS and GMS, respectively. Conversion from GMS to CMS in the case of lines carried mutations in both sterility systems required only S-type cytoplasm donor, while lines carried mutation in single nuclear restorer gene for GMS required not only S-type cytoplasm but also rf allele donors. The important finding is the broader function of maintainer line in certain male sterility system that can be used as a maintainer or restorer line for other male sterility systems. We also confirmed that line CC1 is the general restorer for both CMS and GMS systems.  相似文献   
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Two new tricyclic alkaloids, polycitorols A (1) and B (2) have been isolated along with the known lepadiformine (3) from a marine ascidian of the family Polycitoridae. The structures of the new compounds were elucidated by analysis of NMR data and comparison with those of 3 and other related compounds [15]. Compounds 1 and 2 are closely related to cylindricines A and B, lacking C-4 oxygenation found in cylindricines and having a butyl instead of a hexyl appendage. NOE experiments on compounds 1 and 2 suggested the A/B ring fusion to be cis.  相似文献   
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An initial step in catch and effort analysis is determination of what subset of the data is relevant to the analysis. We propose an objective approach to subsetting trip records of catch and effort data when fishing locations are unknown; the species composition taken on a fishing trip is used to infer if that trip's fishing effort occurred in a habitat where the species of interest (the target species) is likely to occur. We use a logistic regression of multispecies presence–absence information to predict the probability that the target species would be present. A critical value of probability that best predicts target species presence and absence in the data set forms an objective basis for subsetting the trip records. We test this approach by applying it to a data set where individual fishing locations are known, and we show that the method is an effective substitute for information on individual fishing locations.  相似文献   
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Polyphenol oxidase (PPO) of cauliflower was purified to 282-fold with a recovery rate of 8.1%, using phloroglucinol as a substrate. The enzyme appeared as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The estimated molecular weight of the enzyme was 60 and 54 kDa by SDS-PAGE and gel filtration, respectively. The purified enzyme, called phloroglucinol oxidase (PhO), oxidized phloroglucinol (K(m) = 3.3 mM) and phloroglucinolcarboxylic acid. The enzyme also had peroxidase (POD) activity. At the final step, the activity of purified cauliflower POD was 110-fold with a recovery rate of 3.2%. The PhO and POD showed the highest activity at pH 8.0 and 4.0 and were stable in the pH range of 3.0-11.0 and 5.0-8.0 at 5 °C for 20 h, respectively. The optimum temperature was 55 °C for PhO and 20 °C for POD. The most effective inhibitor for PhO was sodium diethyldithiocarbamate at 10 mM (IC(50) = 0.64 and K(i) = 0.15 mM), and the most effective inhibitor for POD was potassium cyanide at 1.0 mM (IC(50) = 0.03 and K(i) = 29 μM).  相似文献   
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Non‐pungent bell pepper (Capsicum annuum L.) lacks the cytoplasmic male sterility (CMS) nuclear restorer allele, Rf, and CMS cannot be employed in its F1 hybrid seed production. To demonstrate that the genic male sterility (GMS) system in non‐pungent bell pepper can be converted to the CMS male sterility system, the conversion of GMS to CMS for non‐pungent bell pepper line GC3 was conducted by introgression of S‐type cytoplasm and the Rf allele from tropical pungent donors. After morphological traits were evaluated, two lines from BC1F1 containing S‐type cytoplasm and four lines from BC2F2 containing Rf allele, phenotypically similar to GC3, were obtained and could be employed as CMS male sterile lines and restorer lines for non‐pungent bell pepper. Four molecular markers potentially linked to traits of interest were also evaluated in BC1F1 and BC1F2 populations. This is the first time that GMS has been successfully converted to CMS in bell pepper, a significant contribution for bell pepper hybrid seed production.  相似文献   
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Paddy and Water Environment - A field experiment was carried out to determine the emissions of nitrous oxide (N2O) and methane (CH4) and yield of rice grains under water management of continuously...  相似文献   
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薯蓣植物的染色体数目与形态特征相关性分析   总被引:1,自引:0,他引:1  
对从中国南方地区搜集的20份山药和19份大薯种质材料进行了形态特征鉴定与染色体计数。结果显示,山药和大薯形态特征丰富,染色体数目为40条或60条,且形态特征与染色体数目存在相关性。  相似文献   
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