Petal-assisted artificial pollination method enhanced the fruit setting ratios in tea plant (<i>Camellia sinensis</i>)

Abstract

<bold/> The pollinated method plays an important role in developing F1 population. Our study presents an improved method of petal-assisted artificial pollination in tea plants. The field operation using this method exhibited high efficiency in which more than 500 pistillate flowers per day can be pollinated per capita, and the pollen amount from only one staminate flower was sufficient to pollinate more than 5 pistillate flowers. Additionally, we surveyed the fruit-setting ratio in three F1 groups, which were established using this method and the influence of rainfall on the fruit-setting ratio. The results indicate that the fruit-setting ratio was superior among the tested F1 population with an average value of 12.90%, and a significant negative correlation was observed between rainfall and fruit-setting ratio. By analyzing the growth states of each F1 population, both a high germination rate and survival rate were observed. Furthermore, the purity for 184 individuals in the F1 population of ‘Jiaming 1’ × ‘Longjing 43’ (J×L) were analyzed with 32 selected simple sequence repeats (SSRs). The purposes of this paper are (1) to demonstrate that this method is beneficial to establish high purity F1 population and (2) to identify the number of SSR markers that are suitable for identification. The parentage analysis detected nine false-hybrid individuals, and the rate of false-hybrid was only 4.89% at 95% confidence, demonstrating that a low false-hybrid rate can be achieved by the method. Furthermore, one to two SSR markers randomly selected from each linkage group or chromosome were recommended as a sufficient quantity for SSR identification.