Pollen viability, pistil receptivity, and embryo development in hybridization of Nelumbo nucifera Gaertn

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 05:00-06:00hrs had the highest viability, and the viabilities of Jinsenianhua and Qinhuaihuadeng were 20.6 and 15.7, respectively. At 4h 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 1d 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. Copyright © 2012 Yan-Li Wang et al.