分子标记在甘蓝遗传育种中的应用

本文综述了分子标记在甘蓝遗传育种中应用的几个方面：1、分子标记遗传图谱的建立；2、亲缘关系和遗传多样性的研究；3、基因定位；4、品种纯度鉴定；5、分子标记辅助选择。     

Agronomic Evaluation of Legume Cover Crops for Sustainable Agriculture

The agronomic characteristics of different legume cover crops and their effects on soil chemical properties were investigated in a short-term field study. We compared weed biomass, nitrogen equivalence, growth rate, leaf chlorophyll content, cover crop biomass, soil total organic carbon, and soil total nitrogen under eight different legume cover crops in a short-term field experiment. We found the highest growth rate, cover crop dry biomass, N plant content, and N contribution with C. ochroleuca plants, whereas for leaf chlorophyll content, soil organic carbon, and total nitrogen the highest values were found with M. pruriens. We did not find any significant difference among C. ochroleuca and M. pruriens for cover crop dry biomass. Our findings suggest that the incorporation of cover crops into the soil can change positively the soil chemical properties, such as soil organic carbon and total nitrogen. Our results also highlight the importance of considering the short-term effect of cover crops on the tropical soil fertility maintenance, in this case, Regosol.     

Vesicular Arbuscular Mycorrhizal (VAM) fungi- as a major biocontrol agent in modern sustainable agriculture system

In the present agricultural system, the discriminate use of synthetic chemical fertilizers has predominantly increased throughout the world. Moreover, using excessive use of fertilizers to increase production deteriorates the various soil qualities and pollute water body environment. So using VAM fungi as a biocontrol agent in modern sustainable agriculture, in terms of various parameters like reduction of damage caused by various pathogens, cost effectiveness, energy saving and also as an environment friendly, is a promising perspective in modern agriculture. Also control of plant pathogens in modern agriculture is presently accepted as a key practice in sustainable agriculture because it is based on the management of certain rhizosphere organisms, common components of ecosystems, known to develop antagonistic activities against harmful organisms. Vesicular Arbuscular Mycorrhizal Fungi interact with other microorganisms in the rhizosphere and various other soil constituents. Upon root colonization by VAMF, there occurs profound physiological changes in the host plant. Present agriculture system increasing demand for low-input agriculture and creates greater interest in soil microorganisms which are able to accelerate plant nutrition, health and improve soil quality. The importance of VAM in incresaing food production is far and wide; therefore these can be used in modern sustainable agriculture particulary as biocontrol agent. This review highlights the different interactions of Vesicular Arbuscular Mycorrhizal Fungi (VAMF) and the rule of these interactions in the biological control of plant pathogens. But the commercial use of Vesicular Arbuscular Mycorrhizal Fungi (VAMF) as biocontrol agents is still in its infancy. The main reason is the poor understanding of the mechanisms of the modes of action of VAM fungi in association with the host plants.     

Increasing water productivity for paddy irrigation in China

This paper introduces the research on practices to increase water productivity for paddy irrigation in China and summarizes the experience on implementation of the alternate wetting and drying (AWD) irrigation technique. The widespread adoption of the AWD practice on 40% of the rice growing area provides an opportunity for China to produce more food in the water-surplus south where it is wet and the traditional based paddy field agriculture is dominant. Physical and institutional measures leading to increasing water and land productivity in rice-based systems are discussed. Research studies show that AWD practice does not reduce rice yield, but does increase the productivity of water. Water use and thus water charges can be reduced. However, experience shows that demonstrations and training are needed to encourage farmer adoption. Furthermore, there are a range of complementary policies and practices, such as volumetric pricing or farm pond development, which provide incentives for adoption of AWD. Finally, there remain many scientific issues to be addressed. Application of the AWD technique in some regions is still very difficult because of both bio-physical and socio-economic problems. In conclusion, the widespread adoption of AWD is only a first step in the continuing effort to find practices that will increase water productivity for paddy irrigation in China.Dr. Yuanhua Li was a Professor and Dean in Wuhan University of Hydraulic and Electric Engineering from 1996 to 2000. After that, he has been a Professor and Deputy Director General of the National Centre for Irrigation and Drainage Development, Ministry of Water Resources, China. He has been doing research on irrigation principally for paddy since 1982.Dr. Randolph Barker is an agricultural economist and Professor Emeritus Cornell University. From 1966 to 1978 he served as head of the Economics Department, International Rice Research Institute, Los Banos, Philippines and from 1995 to 2004 was principal researcher, International Water Management Institute, Colombo, Sri Lanka.     

Vitamin C Enrichment of Fruit Juice Based Ready-to-Serve Beverages Through Blending of Indian Gooseberry (<Emphasis Type="Italic">Emblica officinalis</Emphasis> Gaertn.) Juice

Physiconutritional qualities of fruits viz. apple, lime, pome- granate, Perlette grape, and Pusa Navrang grape were analyzed and compared with those of Indian gooseberry (Emblica officinalis Gaertn.). Indian gooseberry juice contained the highest vitamin C (478.56 mg/100 ml). Hence, when gooseberry juice was blended with other fruits juice for the preparation of ready-to-serve (RTS) beverages, it boosted their nutritional quality in terms of vitamin C content. On the basis of overall sensory quality and vitamin C content, RTS beverage prepared by blending gooseberry and Pusa Navrang grape juice in 20:80 ratio was found to be the best.     

Quantitative trait loci for temperature-sensitive resistance to <Emphasis Type="Italic">Puccinia striiformis</Emphasis> f. sp. <Emphasis Type="Italic">tritici</Emphasis> in wheat cultivar Flinor

Stripe (yellow) rust, caused by Puccinia striiformis Westend. f. sp. tritici Eriks. (Pst), is an important disease of wheat (Triticum aestivum L.) globally. Use of host resistance is an important strategy to manage the disease. The cultivar Flinor has temperature-sensitive resistance to stripe rust. To map quantitative trait loci (QTLs) for these temperature-sensitive resistances, Flinor was crossed with susceptible cultivar Ming Xian 169. The seedlings of the parents, and F₁, F₃ progeny were screened against Chinese yellow rust race CYR32 in controlled-temperature growth chambers under different temperature regimes. Genetic analysis confirmed two genes for temperature-sensitive stripe rust resistance. A linkage map of SSR markers was constructed using 130 F₃ families derived from the cross. Two temperature-sensitive resistance QTLs were detected on chromosome 5B, designated QYr-tem-5B.1 and QYr-tem-5B.2, respectively, and are separated by a genetic distance of over 50 cM. The loci contributed 33.12 and 37.33% of the total phenotypic variation for infection type, respectively, and up to 70.45% collectively. Favorable alleles of these two QTLs came from Flinor. These two QTLs are temperature-sensitive resistance loci and different from previously reported QTLs for resistance to stripe rust.     

A study of the oxygen plasma treatment on the serviceability of a wool fabric

Low temperature plasma (LTP) treatment using oxygen gas was applied to a wool fabric. The LTP treated wool fabric was tested with several methods: ASTM D5035-1995, ASTM D1424-1996, AATCC Test Method 99-2000, AATCC Test Method 61-2001 1A, AATCC Test Method 15-2002 and AATCC Test Method 8-2001 and the results were compared with the industrial requirements (ASTM D3780-02 and ASTM D4155-01). The results revealed that the LTP treated wool fabric could fulfil the industrial requirements. The results of the investigation were discussed thoroughly in this paper.     

Fabrication of nanofibers with ultrahigh production by a facile high pressure air-jet atomized electrospinning

A novel method named as high pressure air-jet atomized electrospinning was proposed to prepare nanofibers with ultrahigh production. The spinning solution with lower concentration and viscosity was cutted into micron-sized droplets by a 700 mesh filter in the front of nozzle and then was crushed and atomized into massive smaller droplets, which were drawn into nanofibers directly under the electric force and airflow force. Flow field under different air pressure was simulated to study its effect on the formation of nanofibers. The airflow showed the minimum pressure and maximum velocity at a location 2 cm away from the spray nozzle, where small droplets cutted were crushed and atomized into massive smaller droplets by the converging airflow. The velocity and distribution region of the airflow increased with increasing air pressure. It showed a smaller diameter of 150 nm and ultrahigh production of 75.6 g/h for nanofibers prepared based on this novel method at the air pressure of 0.8 MPa. The production of nanofibers almost reached thousands of times of that from conventional needle electrospinning.     

根系产生的有机酸对根际土壤养分活化的影响

本试验以采自中国东北3个地点的4种土壤,即棕色针叶林土、暗棕壤、黑土与黑钙土为材料,对根系分泌的两种有机酸及水在活化根际矿质养分方面的作用进行了模拟与比较。结果表明:有机酸能够活化养分,其程度主要取决于有机酸的数量和类型以及供试土壤的理化和生物化学性质;对于所有土壤类型,柠檬酸对Fe, Mn, Cu和Zn的活化效率明显高于苹果酸,而对于P, K, Ca 和Mg的活化效率并不是很高,有时甚至较苹果酸为低;所有元素的溶液浓度均随所加柠檬酸数量的增加而增加。图2表3参9。