Influence of pollination methods on fruit development, fruit yield and oil quality in oil tree peony

Abstract

Insufficient pollination reduces the fruit and seed setting rate and limits the chance of outcrossing in crop plants that are highly dependent on insect pollination, thus affecting the quality and growth rate of progenies. To investigate the effect of pollination methods on the fruit growth rate, fruit yield, oil yield and seed oil quality, four pollination methods, such as (1) in cages with honeybees (Apis mellifera L.), the control in cages with (2) hand pollination, (3) wind pollination, and (4) self-pollination were used to pollinate the flowers of oil tree peony (Paeonia ostii T. Hong et J.X. Zhang). Results showed that the mean growth rate and cumulative growth rate of fruit diameter, follicle length and diameter pollinated by honeybees were significantly higher than that of the control group (hand, wind and self-pollination). Fruit development ratio, seed setting rate and the number of seeds per fruit pollinated by honeybees were significantly higher than self-pollination. Moreover, pollination by honeybees increased yield per fruit by 56.28%, 59.42% and 126.27% compared to the hand, wind and self-pollination, respectively. Compared with hand pollination, the oil yield of honeybee-pollinated tree peony increased by 12.24%. However, the total unsaturated fatty acidcontent of seed oil was not significantly changed with different pollination methods. Our study demonstrated that bee pollination is essential to reach rapid fruit development and high seed yield in oil tree peony.