Pollen-mediated Transformation by Microprojectile Bombardment is Genotype Class Independent in Gossypium hirsutum L.
Oct 8, 2018
The biological characteristics of bombarded pollen were presented by the optimized delivery mode for TM-1, a genetic standard, and 23 Chinese G. hirsutum cultivars, which were collected from 5 ecological regions and derived from 7 ancestors. The results showed that, compared with unbombarded pollen, the average percentage of GUS transient expression of bombarded pollen grains is about 61.12%, the percentage of viable and germinated pollen grains is decreased by 14.34% and 25.83%, respectively. There are remarkable differences as compared with the control by statistical test. Although the biological effects of bombardment on pollen differ among 24 cultivars and the cultivars could be divided into four groups by Star-Site Cluster analysis, differences estimated by mutual information analysis were not related to their ecological type or ancestry. Therefore, pollen-mediated transformation method was independent of genotype. This is not only a new approach to studying the relationship between a plant transformation system and its receptor genotype, but also a first report that the transformation system is genotype-independent. Stigmata sprayed with the screening liquid were pollinated with bombarded pollen grains and seeds were set in 11 cotton cultivars. On average, 2.87 seeds could be set pollinated with one dish bombarded pollen grains. To screen for transgenic plants, the embryonic roots from the resulting seeds were immersed in Hogland solution with 100 mg/L kanamycin. Many plants have survived, and for cotton cultivar “Ji 938” 3.0 % of the plants survived.