Influence Of The Cultured Odontobutis Obscurus To The Microbial Community 、water Quality And Rice Traits In Rice-fish System

1 Preface As is known to all, paddy cultivation mode is a highly efficient and can achieve double harvest. It can not only relieve the contradictions of the agricultural land and farming land, but also in the case of no additional input to increase output. In recent years, rice breeding more and more get the welcome of the broad masses of farmers.Rice- crab farming,rice-fish farming,rice-shrimp farming and rice-ducks farming gradually being used. Research on rice paddy is also more and more get the attention of people.The problem such as the ecological mechanism of rice paddy also slowly into the topic. Odontobutis obscurus as a newly discovered species, the study of its farmed fresh for rare at home and abroad. It is a kind of rare aquatic species, also has the rich connotation and nutritional value. In order to study the influence of the cultured Odontobutis obscurus to the microbial community 、water quality and rice traits in rice-fish system, conduct the rice- Odontobutis obscurus farming experiments, in order to do something useful to the laters.2 Influence of the cultured Odontobutis obscurus to the microbial community structure and diversity in rice-fish systemIn order to study influence of the cultured Odontobutis obscurus to the microbial community structure and diversity in rice-fish system. We investigated the microbial diversity of the water and sediment in rice-fish system using DGGE technology in Haiyan, Zhejiang. In this study, we detected species of Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria, Epsilonproteobacteria,Chlorobi,Acidobacteria,Firmicutes, Actinobacteria,Cyanobacteria. Diversity analysis showed, sediment microbial species in rice-fish system were more than that in conventional rice fields. The Shannon-Weiner index in sediment of the rice-fish system was 2.86 and significantly higher than 2.27 of the conventional paddy fields. The Shannon-Weiner index in sediment was declined from 2.56 to 2.16 along the cultured process in rice-fish system. The analysis results of PCA and DGGE showed the obvious differences of the microbial community structure of water and sediment between rice-fish system and the conventional paddy fields, which indicated the cultured species O. obscurus may play an important role in the Regulation of the microbial community.3 Influence of the cultured Odontobutis obscurus to the water and the change of water quality in rice-fish systemIn order to study influence of the cultured Odontobutis obscurus to the water in rice-fish system and the change of the water quality. We conduct the riceOdontobutis obscurus farming experiments in 2015 in Haiyan, Zhejiang.We calculate the total phosphorus(TP), total nitrogen(TN),ammonia(NH3-N), nitrite nitrogen(NO2--N), nitrate(NO3--N), chlorophyll a(Chla) of rice field water and ditch water in rice-fish system, conventional rice field water. Results show that ammonia nitrogen, nitrite, nitrate nitrogen, total phosphorus can be purified at some degree in rice- Odontobutis obscurus system. In the condition of low levels of total nitrogen it also has certain purification effect. But when the level of total nitrogen is high the purification effect will weak. The changes of the level of ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, total indicators in rice field water and ditch water in rice-fish system is consistent.4 Influence of the cultured Odontobutis obscurus to rice production and processing quality in rice-fish systemIn order to study influence of the cultured Odontobutis obscurus to rice panicle, seed setting rate and grain yield traits and the roughness, polished rice rate, grain of aspect ratio in rice-fish system. We conduct the rice- Odontobutis obscurus farming experiments in 2015 in Haiyan, Zhejiang. Experiment is divided into the cultured Odontobutis obscurus group and conventional paddy fields group, after the rice harvest, determined rice panicle, seed setting rate and grain yield traits and the roughness, polished rice rate, grain of aspect ratio. Finally the experimental results show that the group of cultured Odontobutis obscurus, grains per spike(165.38), thousand-grain weight(27.10) and setting rate(88.48%) more than conventional rice field(grains per spike(156.52), thousand-grain weight(24.19) and setting rate(82.16%)). At the same time the Odontobutis breeding paddy fields have increased rice grain width(Odontobutis breeding paddy fields(2.96mm), conventional rice(2.83mm)). And reduce the rice grain length to width ratio(Odontobutis obscura paddy farming 1.74, conventional paddy fields 1.81); but rice out brown rice rate, milled rice rate and grain length had no obvious change. Reflect Odontobutis obscura paddy farming model of yield traits in rice has positive effect, and has certain effect on rice appearance quality.