Are matching patterns of male and female flowers in response to nutrient supply and pollen concentration optimal for fruit and seed growth?

Abstract

Background: 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 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. Results: We found that the nutrient supply significantly increased the number of female flowers, although the number of female flowers did not increase with the strength of the pollination. The number of male flowers did not decrease even under the low nutrient concentration; consequently, the matching pattern of male and female flowers reflects the response of plants to nutrients and nutrient resources during flowering stage. Pollination treatment affected the fruit growth, seed set, and fruit yield. However, the number of fruit, fruit set percentage, and total seeds per plant did not increase with the pollination level, although individual fruit weight and seed number in one fruit did increase. Conclusions: It is concluded that the response of cucumber flowering to external factors is direct and instantaneous, and this matching pattern of male and female flowers may not be optimal for fruit development and seed formation. Keywords: Cucumber, Plant fitness, Sex differentiation, Monoecious, Pollen resource