福建省水稻霜霉病诊断和病原鉴定

水稻霜霉病诊断特征为植株矮缩,叶片黄化、产生黄褐色条斑.利用显微镜检查染色病组织内的病原菌藏卵器和卵孢子,通过观察病原菌的培养性状、形态特征和致病性测定,该病原菌被鉴定为大孢指疫霉水稻变种.

Quantitative Relationship between Leaf Area Index and Canopy Reflectance Spectra of Rice under Different Nitrogen Levels

Monitoring rice growth by spectral remote sensing technology can provide scientific basis for the high yield and efficient production of rice. Field experiments with different nitrogen application amounts using Tianyouhuazhan rice as test sam- ples were set up to study the relationship between rice leaf area index （LAI） and canopy reflectance spectral. The results showed that： the LAI increased with the amount of applied nitrogen; the canopy reflectance spectral showed significant re- sponse characteristics to groups with different nitrogen application levels; the corre- lation coefficient of LAI and canopy spectral reflectance reached the maximum at 720 nm red edge region. The mathematical model was constructed to predict the LAI according to the canopy reflectance spectra of rice.

Preliminary Study on Spectra Diagnosis Model for Nitrogen Nutrition in Rice Leaf

[Objective] The aim was to build spectral diagnosis model for nitrogen nutrition in rice leaf.[Method] Through determination of transmission,absorption spectra and nitrogen content on rice leaves of different rice varieties（Xiangyou 109 and Shanyou 98）,different growth periods and different nitrogen levels,we analyzed the correlation between leaf spectra and their nitrogen contents,and built prediction model of spectral index for nitrogen content in rice leaf.[Result] The detection precision of this model was above 80% that can be used on diagnosing of rice nitrogen nutrition.[Conclusion] The study provided evidence for monitoring nitrogen nutrition status of rice.

良种场如何实现良性循环

国有农牧渔良种场是指水稻良种场、畜牧良种场、水产良种场和园艺场,属全民所有制的生产性事业单位,是提供优良种子、种畜、种苗的生产基地,承担了为农业良(原)种的繁育、示范、保种、新品种试验和新技术推广等许多重要任务,为我国农业的持续发展和增产增收作出了重要贡献。同时,也为社会提供了—定数量的粮、畜、禽、鱼、果等多种农副产品,为丰富人们的“米袋子”、“菜篮子”作出了较大努力。但随着社会主义市场经济的迅速发展,国有农牧渔良种场也面临着许多压力和挑战。如何使它们摆脱困境,走出—条行之有效的发展路子,是当前亟待解决的问题。

Effects of Different Organic Residues on Rice Yield and Soil Quality

Calcaric regosols are a valuable land resource, distributed widely across western China. Soil quality has deteriorated considerably in recent years owing to the blind pursuit of economic benefits. A 2-year field experiment was carried out to evaluate the effects of using spent mushroom compost, leguminous plant (Vicia sepium L.) compost, and a combination of the two (at a 1:1 and 2:1 ratio), on rice yield and soil quality in a suburb of China. Vicia sepium L. composted with spent mushroom compost at a 1:1 ratio produced the highest grain and stover yield, grain and stover phosphorus concentration, and phosphorus uptake of rice; they were 56.5%, 93.2%, 89.3%, 198.6% and 22.2% greater than control soil, respectively. The 2:1 ratio (Vicia sepium L.: spent mushroom compost) produced the highest grain N concentration, stover N concentration, and N uptake; they were 31.6%, 31.4%, and 40.7% higher than control, respectively. Soil physical, chemical, and environmental properties were improved with the application of Vicia sepium L. composted with spent mushroom compost at a 2:1 ratio. In particular, soil water-stable aggregates, organic carbon, particulate organic carbon, total nitrogen, available potassium, and cation exchange capacity increased, whereas bulk density, pH, and phytoavailable heavy metals decreased. This organic treatment is beneficial to improve soil quality indicators, and contribute to soil restoration.

Chemical and Microbiological Parameters of Paddy Soil Quality as Affected by Different Nutrient and Water Regimes

A field experiment was conducted from 1999 to 2002 to compare and evaluate the effects of nutrient and water regimes on paddy soil quality by investigating soil chemical and microbiological parameters. Four nutrient regimes, a control, chemical fertilizers only (CF), chemical fertilizers with swine manure (SM), and chemical fertilizers with wheat straw (WS), and two soil moisture regimes, continuous waterlogging (CWL) and alternate wetting and drying (AWD), were investigated. With SM and WS total organic carbon and total nitrogen in the paddy soil were significantly higher (P < 0.05) than those with CF. A similar effect for organic amendments was observed in the soil light fraction organic C (LFOC), water-soluble carbohydrates (WSC), and water-soluble organic C (WSOC). CWL, in particular when swine manure was incorporated into the paddy soil, markedly decreased soil redox potential (Eh) and increased total active reducing substances (ARS). Meanwhile, as compared to CF, SM and WS significantly (P < 0.05) increased soil microbial biomass C (MBC) and mineralizable carbon, with differences in AWD being higher than CWL. In addition, SM and WS treatments significantly (P < 0.05) improved rice above-ground biomass and grain yield, with AWD being greater than CWL. Thus, for ecologically sustainable agricultural management of paddy soils, long-term waterlogging should be avoided when organic manure was incorporated into paddy soil.

Effects of High-temperature Damage on Rice Growth and Its Countermeasures

This study introduced the effects of high-temperature damage on rice and reviewed the damage mechanism, heat damage index and risk assessment, forewarning and monitoring. On the basis of extensive studies, this paper put forward the viewpoints of ascertaining the fundamental mechanism of high temperature damage to rice at the molecular level, establishing a comprehensive heat damage index taking variety, growth stage and other meteorological factors into consideration, selecting appropriate sowing time, choosing heat-resistant varieties and improving the prevention system. All of these are aimed at providing a solid foundation for coping avoiding the harms from heat damage and improving the coping method.

Construction of Oryza sativa genome contigs by fingerprint strategy

We described the construction of BAC contigs of the genome of a indica variety of Oryza sativa, Guang Lu Ai 4.An entire representative (sixfold coverage of rice chromosomes) and genetically stable BAC library of rice genome constructed in this lab has been systematically analysed by restriction enzyme fragmentation and polyacrylamide gel electrophoresis. And all the images thus obtained were subject to image-processing, which consisted of preliminary location of bands, cooperative tracking of lanesby correlation of adjacent bands, a precise densitometric pass, alignment at the marker bands with the standard,optional interactive editing, and normalization of the accepted bands. The contigs were generated based on the Computer Software specially designed for genome map ping. The number of contigs with 600 kb in length on average was 464; of contigs with 1000 kb in length on average was 107; of contigs with 1500 kb in length on average was 23. Therefore, all the contigs we have obtained amounted up to 420 megabases in length. Considering the size of rice genome (430 megabased), the contigs generated in this lab have covered nearly 98% of the rice genome. We are now in the process of mapping the contigs to chromosomes.

Screening of Drought Resistance Identification Indexes for Rice(Oryza sativa L.) Cultivars in Ningxia

The morphological characters, physiological characters, yield traits and yield per plant of total 49 rice cultivars from Ningxia were investigated under conditions of water stress and non-water stress so as to determine the relationship between each trait and yield per plant under water stress and the relationship between each relative character and drought resistance coefficient under water stress and non-water stress. The correlation, grey correlation, stepwise regression and path analyses showed that the tiller number per plant, plant height, grain density, effective panicle number per plant and grain number per panicle, total 5 traits, were significantly correlated with the drought resistance of rice, and they could be used to identify the drought resistance of rice in Ningxia. In addition, the drought resistance of rice was graded qualitatively according to the subordinate function value of corresponding drought resistance coefficient. The results showed that among the 49 rice cultivars from Ningxia,6 rice cultivars were highly drought resistant, and 9 rice cultivars were moderately drought resistant, suggesting that the evaluation method was feasible and effective.