Pollen Vigor Test And Controlled Pollination In Three Acacia Species

This paper systematically studied the technical system of pollen vigor test and controlled pollination technology of Acacia auriculiformis,A.mangium and A.crassicarpa,mainly including: pollen collection,storage,the suitable conditions of in vitro pollen germination,the methods of pollen vigor test of three Acacia species and controlled pollination of Acacia auriculiformis and A.mangium.It lays the foundation for choosing and creating excellent new hybrid breeding varieties by further controlled pollination in the future.In addition,the factors that affect podding rate were analyzed emphatically.The findings will provide theoretical basis for orchard management of Acacia.The main conclusions are as follow:1.The three Acacia species fresh inflorescences were took back to the chamber and air dried at room temperature before 9:00 in the morning.On the next day after 10:00,using the brush method to collect pollen.The collected pollen were stored at room temperature?25-30??,5? and-20?.2.The most suitable in vitro pollen germination condition of A.auriculiformis was that of 200 g·L-1 sucrose,300 mg·L-1 boric acid and the 30? culture temperature.The most suitable in vitro pollen germination condition of A.mangium was that of 200 g·L-1 sucrose,100 mg·L-1 boric acid and the 28? culture temperature.The most suitable in vitro pollen germination condition of A.crassicarpa was that of 150 g·L-1 sucrose,100 mg·L-1 boric acid and the 24? culture temperature.3.The fresh A.auriculiformis pollen germination rate was 98.26%.The fresh A.mangium pollen germination rate was high?94.28%?.The fresh A.crassicarpa pollen germination rate was the highest reached 93.79%.The three Acacia species pollen stored at-20?,the germination rate was significantly higher than which stored at 5? and room temperature.After stored 365 days at-20?,A.auriculiformis Pollen germination rate was 53.37%,the A.mangium germination rate was 94.82%,A.crassicarpa pollen germination rate was 29.72%.After stored 2190 days at-20?,A.auriculiformis pollen germination rate was 12.57%,A.mangium pollen germination rate was 66.77%.There were no significant difference of three Acacia species pollen vigor detected by Peroxidase and I2-KI staining method.4.With 50 mg·L-1 and 250 mg·L-1 of Ca²⁺ or without Ca²⁺ in the most suitable in vitro pollen germination condition the germination rate of A.auriculiformis pollen were higher than 80%.The higher of Ca²⁺ concentration,the lower of the pollen germination percentage.With the increase of Ca²⁺ concentration,the pollen germination rate and pollen tube length were restrained.Without Ca²⁺ in the most suitable in vitro pollen germination condition the pollen germination rate of A.mangium was as high as 94.27%.When Ca²⁺ concentration was higher,the pollen germination percentage and pollen tube length increased with the rise of Ca²⁺ concentration,while when Ca²⁺ concentration was higher than 200 mg·L-1,the pollen germination rate and pollen tube length was restrained with the rise of Ca²⁺ concentration.The more the Ca²⁺ concentration,the more severe the restrained was.Without Ca²⁺ and with 250 mg·L-1 of Ca²⁺ in the most suitable in vitro pollen germination condition,the pollen germination rate of A.crassicarpa was up to 93.97% and 96.23% respectively.5.Podding rate through open pollination was very low of A.auriculiformis and A.mangium.The controlled pollination podding rate achieved the highest by using the sprayer method + brush method with cultured pollen.The controlled pollination podding rate could be improved to16.42% of A.auriculiformis 5 as female parent and A.mangium 2 as male parent which was culture.The average highest seed germination rate of controlled pollination was 88.00%.The average highest height of seed seedling?7 months?was 43.07 cm.6.Acacia self-incompatible and the visiting insects led to the higher risk of Acacia selfing,which were the main reasons for the low podding rate of Acacia seed orchard.