Edible Peanut Worm(Sipunculus nudus) in the Beibu Gulf： Resource, Aquaculture, Ecological Impact and Counterplan

Sipunculus nudus is an important economic species because of its high nutritional and medicinal values. The exploitation and utilization of S. nudus primarily occur in the coastal regions of the Beibu Gulf. However, wild resource of S. nudus is rapidly decreasing because of the overexploitation, which has led to considerable developments of artificial breeding techniques. The cultivation scale of S. nudus has increased in response to successful artificial breeding; however, methods for culturing S. nudus in tidal flats or ponds require further study. Most studies have focused on the breeding, nutrition, medical value and ecological impact of these worms. Studies on the distribution, sediment requirements, nutrition characteristics, breeding techniques and aquaculture ecology of this species are summarized in this paper to promote the development of the aquaculture industry for S. nudus. The high biomass of S. nudus in the Beibu Gulf is positively correlated with the sediment characteristics and water quality of the region. The production of peanut worm has improved to some extent through culturing; however, the nutrient value and ecological environment problems have been observed, which reflect the over exploitation of trace elements and the sediment. These problems will worsen unless they are resolved, and the release of organic materials, nitrogen and phosphorus during harvesting impacts the coastal environment. Moreover, genetic erosion is a potential risk for larvae in artificial breeding programs in tidal flats. Therefore, culturing and collecting methods should be improved and the wild resource conservation should be implemented to promote the sustainable development of the peanut worm.

Study on the Harmonious Symbiosis of Rice,Loach and Frog

The harmonious symbiosis of rice,loach and frog is a new stereo,ecological,high-efficiency agricultural development mode that integrates cultivation and breeding.On the one hand,it protects ecological environment and increases peasants＇ income;on the other hand,it ensures food security and human health.This mode produces outstanding economic,ecological and social benefits.

Evaluation of Brazilian wild Hevea germplasm for cold tolerance：genetic variability in the early mature growth

Hevea brasiliensis is a commercially cultivated species for its natural rubber（NR） latex in South East Asian countries. To meet the ever-increasing demand, NR cultivation has been extended to non-traditional regions due to the limited scope of further expansion in traditional rubbergrowing areas in India. These areas are often confronted with various abiotic stresses, especially high and low temperatures, which cause reduction in plant growth, thereby increasing its uneconomical immaturity period. Eighteen wild Hevea accessions along with two modern clones RRII203 and PB 235 and two check clones RRIM 600 and Haiken 1 were evaluated in the early mature growth phase.The site was at Nagrakata, West Bengal, the sub-Himalayan cold-prone region of India. In Hevea, crop production is governed by two major factors, growth-vigor and production capacity. Growth-vigor is of special importance because the production of rubber is a process linked with the early growth of the plant, which results in early tappability and early economic gains. The genotypes exhibited highly significant clonal differences（P = 0.05） for all the growth traits. Tappability percentage in the seventh year, ranged from 0.33 %（AC 3074, AC 3075, AC 3293） to 89.67 %（RO 2727）. The most vigorously growing accession（RO2727） reached tappabile girth early in the seventh year when the girth of plant ranged from 22.38 cm（AC 3293） to53.12 cm（RO 2727）. The general mean was 43.32 cm, and the similar growth trend was exhibited by these accessions in the tenth year also. Annual girth increment（cm a-1） over3 years ranged from 1.81 cm（AC 3075） to 6.80 cm（RO2727）. The mean winter girth increment（cm a-1） over4 years ranged from 0.13 cm（AC 3075） to 0.96 cm（RO2727） as compared to the check clone RRIM 600（1.11 cm）and Haiken 1（1.10 cm）. Wide differences between the phenotypic coefficient of variation（50.29） and genotypic coefficient of variation（24.82） were observed for winter girth increment. Girth in the tenth year recorded the highest heritability（87 %）. Girth was significantly correlated with the other growth traits. The top 30 % of the potential accessions showing high growth vigour and early tappability under cold stress were identified. These ecotypes/selections have high potential value for the development of coldtolerant clones for these regions and also in broadening the genetic base of the present-day cultivated rubber.

Benin Farmers Advance Through Chinese Agrotechnology

THE fluttering red,five-starred Chinese national flag guided us to the China-aided Agrotechnology Demonstration Center in Seme,20 or more km east of Cotonou,Benin＇s largest city.It stands within a gray-tiled,white-walled Chinese garden-style compound.＂Over the past several years,groups of Chinese agricultural experts and management staff have come to Benin to cooperate with locals in crop cultivation and breeding,animal husbandry and poultry, so speeding up Benin＇s agricultural development and contributing to the country＇s poverty reduction drive,＂ general manager of the center Huang Jianping said.