The Species And Distribution Of INA Bacteria On Banana In Fujian Province And It's Relationship With The Freezing Injury Of Banana

Banana(Musa supientum)is tropical fruit tree which is very sensitive to the temperature.Banana cultivation in China is mainly distributed in tropical and sub- tropical regions of South China,Fujian province is one of the major banana production area. Due to the influence of the winter monsoon climate,chilling injury and frost damage often occurs, which have a great impact to banana production and to be the main factor to limit the development of banana. So, taking some effective measures to defense those damages have become a urgent problem. INA bacteria is widespread in nature, Research has shown that INA bacteria can induce plant cell water ice up and frost occurrence which could aggravate the impact of frost damage to plants.The discovery of INA bacteria provide a new direction to research and control the chilling and frost injury to plants.Thise experiment has studied the relations between the INA bacteria and the banana chilling(frost) injury.At the same time we investigated the density, the ice nucleus active grade and the bacteriology classification of INA bacteria on banana in Fujian Province. Also, we have tested the protective effects of the Pharmacy FS1 on bananas by field experiments, made the positive exploration to prevent chilling and frost injury to banana.(1) Research shows that treatment to banana seedling which has no INA bacteria inoculated at the temperature of 5℃for 24h, slightly chilling injury occured, a obvious symptoms of chilling injury appeared after 48 hours.The Chilling injury is more serious after INA bacteria inoculated,and the higher the concentration of INA bacteria we inoculated , the more serious of the chilling injury happened to banana seedling. Compared with banana which has no INA bacteria inoculated ,the relevant protective enzymes is lower,the raise of MDA and conductivity is more obvious, the banana leaf photosynthesis is hampered more seriously after low temperature stress. To sum up , the study proved that the ice nucleation bacteria not only can induce and increase plant frost damage at the temperature which≤-1℃,but also can increase and induce plants chilling injury at the temperature which between 0 and 5℃.(2) The results show that INA bacteria is very common exist in banana in Fujian Province,the colonization density are mostly more than 104cfu/g,the ice nucleus active grade achieves medium and medium above occupies the total strain number 85.2%,such colonization density and activity levels are sufficient to induce and aggravate the frost damage to banana.So,attention should be paid and some precautionary measures should be taken.Separated 54 ice nucleus bacterias from 60 frost damage specimens which collected from various bananas production area in Fujian Province. The identification results show that there are 42 strains of Erwinia genus,of which E.ananas 36 strains,E.hebicola 6 strains. The other 12 strains are Pseudomonas genus,of which P. sp 6 strains and P. fluorescens 6 stains. The distribution of species of INA bacteria on banana in Fujian province are mainly E.ananas which occupies the total strain num- ber 66.7%.(3)Research shows that by reducing the ice nucleation bacteria can reduce the chilling and frost damage to banana. Determined that there are no phytotoxicity to banana and have a good killing effect to INA bacterias when the pharmacy FS1 is diluted 500 times.The time of drug administration should before the cold wave or the frost approach ,Application period is 7 days, a total of 3 to 4 times.The field experiment shows that pharmacy FS1 can effectively kill the INA bacteria, and have a good protective effect on banana frost damage . Verify that the pharmacy FS1 have great promotional value.