The Patterns of Male and Female Flowers in Flowering Stage May Not Be Optimal Resource Allocation for Fruit and Seed Growth.

Lei Gao,Changlian Peng,Guozhu Yu,Fangyu Hu,Weihua Li,Zhiqi Li

doi:10.3390/plants10122819

Abstract

Changes in the proportions of male and female flowers in monoecious plants in response to external environmental conditions are directly related to the reproductive fitness of plants. The monoecious cucumber (Cucumber sativus) plant was used in this study to assess the responses of sex differentiation and the breeding process to nutrient supply and the degree of artificial pollination using pollen solutions of different concentrations. We found that the nutrient supply significantly improved the number of female flowers, while pollination treatments did not obviously increase the number of male flowers. Continuous pollination changed the number of female flowers especially in the later stage of the pollination experiment. Therefore, pollination changed the ratio of male and female flowers in the flowering stage of cucumber. Pollination treatment affected the fruit growth, seed set, and fruit yield. The number of fruit, fruit set percentage, and total seeds per plant did not increase with the pollination level, but individual fruit weight and seed number in one fruit did increase. The differentiation of male and female flowers in the flowering stage of cucumber is a response to nutrient and pollination resources, but this response is not the optimal resource allocation for subsequent fruit development and seed maturity, which suggests that the response of plants to external environment resources is short-term and direct.

Highlights

Responses by the plant’s reproductive system to external resources and the environment are central to the study of plant evolution [1,2]
The results showed that the total number of male and female flowers in cucumber was significantly higher under high nutrient conditions than that in low nutrient conditions, but pollination intensity did not significantly increase the total number of female and male
The response of female flowers to nutrients was more obvious, the number of female flowers under high nutrient conditions was higher than that under low nutrient conditions (Table 1), and it was statistically significant under the treatment of pollination levels P1, P2, and P4 (Figure 1), indicating that the highest number of female flowers did not correspond with the highest pollination level (Figure 1)

Summary

Introduction

Responses by the plant’s reproductive system to external resources and the environment are central to the study of plant evolution [1,2]. As the resources needed for the growth of roots and leaves, flowering, fruiting, and seed production are not the same, the plant’s investment in these activities is not fixed [6,7], and the resources are finite and result in life history trade-offs in plants [8]. Floral display is fundamental to plant fitness; it will affect pollinator visitation rate and total seed production [9]. There are trade-offs in reproductive allocation between flower size and number [12], fruit weight and seed number for the optimal fitness [13,14]

Methods

Results

Discussion

Conclusion