Pollen Viability, Pistil Receptivity, and Embryo Development in Hybridization ofNelumbo nuciferaGaertn

Yan-Li Wang,Zhi-Yong Guan,Fa-Di Chen,Nian-Jun Teng,Wei-Min Fang

doi:10.1100/2012/678706

Abstract

Seed set is usually low and differs for different crosses of flower lotus (Nelumbo nucifera Gaertn.). The reasons remain unknown, and this has a negative impact on lotus breeding. To determine the causes, we carried out two crosses of flower lotus, that is, “Jinsenianhua” × “Qinhuaihuadeng” and “Qinhuaihuadeng” × “Jinsenianhua” and pollen viability, pistil receptivity, and embryo development were investigated. The pollen grains collected at 05:00-06:00 hrs had the highest viability, and the viabilities of “Jinsenianhua” and “Qinhuaihuadeng” were 20.6 and 15.7%, respectively. At 4 h after artificial pollination, the number of pollen grains germinating on each stigma reached a peak: 63.0 and 17.2 per stigma in “Jinsenianhua” × “Qinhuaihuadeng” and “Qinhuaihuadeng” × “Jinsenianhua”, respectively. At 1 d after artificial pollination, the percentages of normal embryos in the two crosses were 55.0 and 21.9%, respectively; however, at 11 d after pollination, the corresponding percentages were 20.8 and 11.2%. Seed sets of the two crosses were 17.9 and 8.0%, respectively. The results suggested that low pistil receptivity and embryo abortion caused low seed set in “Qinhuaihuadeng” × “Jinsenianhua”, whereas low fecundity of “Jinsenianhua” × “Qinhuaihuadeng” was mainly attributable to embryo abortion.

Highlights

The lotus (Nelumbo nucifera Gaertn.) is an economically important aquatic plant in the family of Nelumbonaceae
There have been some new lotus cultivars developed by traditional hybridization breeding in the past two decades in China, reproductive barriers often exist in artificial hybridization and seriously reduce the breeding efficiency of lotus [6]
Since pollen grains collected at 5:00-6:00 hrs had the highest viability for both cultivars, we carried out artificial pollination experiments using pollen grains collected in this time span

Summary

Introduction

The lotus (Nelumbo nucifera Gaertn.) is an economically important aquatic plant in the family of Nelumbonaceae. Various breeding methods including artificial hybridization, radiation techniques, and multiploid approach have been applied to develop new lotus cultivars [6,7,8]. Among these methods, artificial hybridization is the most widely used and most effective way to produce new lotus cultivars. There have been some new lotus cultivars developed by traditional hybridization breeding in the past two decades in China, reproductive barriers often exist in artificial hybridization and seriously reduce the breeding efficiency of lotus [6]. Few studies have examined reproductive barriers in lotus hybridization, the factors affecting the breeding efficiency of flower lotus remain unknown

Objectives

Methods

Results

Conclusion