两系稻制种穗期病害发生较重的原因及防治措施

调查分析稻粒黑粉病、穗颈稻瘟等两系杂交稻制种穗期主要病害的发生原因,提出了清除菌源、轮换制种、健身栽培、对口药剂防治等防治措施。     

浙江地区不同品种紫花苜蓿不同刈割期二茬性状表现

对不同秋眠级别的紫花苜蓿Medicago sativa品种进行适应性试验,研究不同品种不同刈割期株高、分蘖数、根系、茎叶比及生物学产量间的变化,为生产推广提供指导.     

Based serum metabolomics analysis reveals simultaneous interconnecting changes during chicken embryonic development

Metabolic disorder is a major health problem and is associated with a number of metabolic diseases. Due to native hyperglycaemia and resistance to exogenous insulin, chickens as a model had used in the studies of adipose tissue biology, metabolism and obesity. But no detailed information is available about the comprehensive changes of serum metabolites at different stages of chicken embryonic development. This study employed LC/MS‐QTOF to determine the changes of major functional metabolites at incubation day 14 (E14d), 19 (E19d) and hatching day 1 (H1d), and the associated pathways of differential metabolites during chicken embryonic development were analysed using Metabolite Set Enrichment Analysis method. Results showed that 39 metabolites were significantly changed from E14d to E19d and 68 metabolites were significantly altered from E19d to H1d in chicken embryos. Protein synthesis was promoted by increasing the concentrations of L‐glutamine and threonine, and gonadal development was promoted through increasing oestrone content from E14d to E19d in chicken embryos, which indicated that serum glutamine, threonine and oestrone contents may be considered as the candidate indicators for assessment of early embryonic development. 2‐oxoglutaric acid mainly contributed to enhancing the citric cycle, and it plays an important role in improving the growth of chicken embryos at the late development; the decreasing of L‐glutamine, L‐isoleucine and L‐leucine contents from E19d to H1d in chicken embryonic development implied their possible functions as the feed additive during early posthatch period of broiler chickens to satisfy the growth. These results provided insights into understand the roles of serum metabolites at different developmental stages of chicken embryos, it also provides available information for chicken as a model to study metabolic disease or human obesity.     

Evaluation of Cold Tolerance in NERICAs Compared with Japanese Standard Rice Varieties at the Reproductive Stage

New Rice for Africa (NERICA) is a general name for interspecific rice varieties derived from a cross between the high‐yielding Asian rice (Oryza sativa L.) between locally adapted African rice (Oryza glaberrima Steud.). Eight NERICAs were evaluated for cold tolerance (CT) at the reproductive stage and compared with their O. sativa parents and three Japanese standard rice varieties over 3 years. Cold tolerance was evaluated based on the filled grain ratio (FGR) after cold water irrigation. The FGR was greatly reduced by cold water irrigation. NERICA 1, 2 and 7 had higher FGR (51.9–57.9 %), while NERICA 6, 15 and 16 had lower FGR (6.2–14.5 %). NERICA 1, 2 and 7 were less affected by cold stress, with a 31 % mean reduction in FGR, while NERICA 6, 15 and 16 were greatly affected, with their FGRs being reduced by more than 80 %. NERICA 3 and 4 were moderately affected by cold stress, with about 45 % reduction rate in FGR. FGR significantly influenced the grain weights of the varieties with strong positive correlations (r = 0.83–0.91; P < 0.001), and thus, similar trends in grain weights were observed. Grain weights were reduced by 61.7–96.4 % under cold stress. NERICA 1, 2 and 7 showed significantly better performance than NERICA 3 and 4, while NERICA 6, 15 and 16 performed poorly under cold water irrigation. The Japanese varieties Koshihikari (very tolerant) and Ozora (moderately tolerant) were more affected by cold water irrigation than NERICA 1, 2 and 7. On the basis of the mean reduction rate (%) in FGR under cold stress, the varieties were classified as follows: NERICA 1, 2 and 7 as tolerant; NERICA 3 and 4 as moderately tolerant; and NERICA 6, 15 and 16 as susceptible to cold stress. However, NERICA 7 grain yields were lower under cold stress due to both greatly reduced number of panicles per plant and number of spikelets per panicle. Therefore, NERICA 1 and 2 are suitable candidates for production in the highland regions of East Africa and should be promoted for production.     

Organic farming fosters agroecosystem functioning in Argentinian temperate soils: Evidence from litter decomposition and soil fauna

Benefits of organic farming on soil fauna have been widely observed and this has led to consider organic farming as a potential approach to reduce the environmental impact of conventional agriculture. However, there is still little evidence from field conditions about direct benefits of organic agriculture on soil ecosystem functioning. Hence, the aims of this study were to compare the effect of organic farming versus conventional farming on litter decomposition and to study how this process is affected by soil meso- and macrofauna abundances. Systems studied were: (1) organic farming with conventional tillage (ORG), (2) conventional farming with conventional tillage (CT), (3) conventional farming under no-tillage (NT), and (4) natural grassland as control system (GR). Decomposition was determined under field conditions by measuring weight loss in litterbags. Soil meso- and macrofauna contribution on decomposition was evaluated both by different mesh sizes and by assessing their abundances in the soil. Litter decomposition was always significantly higher after 9 and 12 months in ORG than in CT and NT (from 2 to 5 times in average), regardless decomposer community composition and litter type. Besides, mesofauna, macrofauna and earthworm abundances were significantly higher in ORG than in NT and CT (from 1.6 to 3.8, 1.7 to 2.3 and 16 to 25 times in average, respectively for each group). These results are especially relevant firstly because the positive effect of ORG in a key soil process has been proved under field conditions, being the first direct evidence that organic farming enhances the decomposition process. And secondly because the extensive organic system analyzed here did not include several practices which have been recognized as particularly positive for soil biota (e.g. manure use, low tillage intensity and high crop diversity). So, this research suggests that even when those practices are not applied, the non-use of agrochemicals is enough to produce positive changes in soil fauna and so in decomposition dynamics. Therefore, the adoption of organic system in an extensive way can also be suggested to farmers in order to improve ecosystem functioning and consequently to achieve better soil conditions for crop production.     

基于分段波形的信号瞬时频率计算方法

针对局部均值分解（Local Mean Decomposition，LMD）中乘积函数（Product Function，PF）分量的瞬时频率计算问题，引入了一种新的信号瞬时频率计算方法.该方法基于分段波形，先将信号分成若干个全波段（full wave），然后以一组递增的反正弦函数定义每个全波段的瞬时相位，进而得到信号的瞬时频率.由该方法得到的瞬时频率理论上是正的、稳定的并且能够确保信号局部特征信息的完整.应用该方法计算了仿真信号和实际齿轮故障振动信号的瞬时频率，并与其他方法求得的瞬时频率进行了对比.结果表明，本文方法非常适合求取信号的瞬时频率.     

蓝果忍冬成熟期结合力变化规律的测试分析

为了弄清成熟蓝果忍冬结合力的特性和变化规律、给机械化收获提供技术依据,在蓝果忍冬成熟期间对4个常见品种果实结合力进行了为期16天的跟踪测试。通过分析研究得出:所测试的4个蓝果忍冬品种的结合力分布在0.1~1.7 N之间(P0.05),各品种结合力分布区间略有不同,所测试的野生阿尔泰忍冬、蓓蕾的结合力高于蓝鸟和长白山野生蓝靛果忍冬;各品种结合力随时间呈现出不同程度的下降趋势;同一天内下午的结合力显著大于上午的结合力(P0.05);晴天与阴雨天的结合力无显著性差异。通过因子分析,可将影响结合力的因素测试时间、上下午、相对湿度、温度及天气状况转换成环境因子和时间因子。     

芮城县小麦扬花后期病虫害防治技术

通过对小麦田间后期观测,针对芮城县小麦栽培区,提出小麦扬花后期病虫害防治技术,进而促进该县小麦高产、高效生产。     

Association analysis for detecting significant single nucleotide polymorphisms for phosphorus-deficiency tolerance at the seedling stage in soybean [Glycine max (L) Merr.]

Tolerance to low-phosphorus soil is a desirable trait in soybean cultivars. Previous quantitative trait locus (QTL) studies for phosphorus-deficiency tolerance were mainly derived from bi-parental segregating populations and few reports from natural population. The objective of this study was to detect QTLs that regulate phosphorus-deficiency tolerance in soybean using association mapping approach. Phosphorus-deficiency tolerance was evaluated according to five traits (plant shoot height, shoot dry weight, phosphorus concentration, phosphorus acquisition efficiency and use efficiency) comprising a conditional phenotype at the seedling stage. Association mapping of the conditional phenotype detected 19 SNPs including 13 SNPs that were significantly associated with the five traits across two years. A novel cluster of SNPs, including three SNPs that consistently showed significant effects over two years, that associated with more than one trait was detected on chromosome 3. All favorable alleles, which were determined based on the mean of conditional phenotypic values of each trait over the two years, could be pyramided into one cultivar through parental cross combination. The best three cross combinations were predicted with the aim of simultaneously improving phosphorus acquisition efficiency and use efficiency. These results will provide a thorough understanding of the genetic basis of phosphorus deficiency tolerance in soybean.