Evaluation of rose varieties for pollen efficiency

Abstract

An experiment was conducted to study the pollen viability, in vitro pollen germination, absolute pollen viability, pollen diameter and hip set in ten varieties of rose namely; Africa Star, Century Two, Dr Bharat Ram, Eiffel Tower, Folklore, Gold Medal, Kiss of Fire, Pinata, Pusa Ajay and Sadabahar. Five treatments were used for in vitro pollen germination, viz., control (distilled water) (T1), 15% sucrose (T2), 20% sucrose (T3), 15% sucrose + 100 mg/l boric acid (T4), 20% sucrose + 100 mg/l boric acid (T5). Ten varieties were crossed with three female parents, viz., Queen Elizabeth, Pink Parfait and Raktagandha in the field and hip set was noted. Pollen viability varied from 6.45 (Folklore) to 78.07% (Africa Star) among the varieties. The percentage pollen germination was highest in Dr Bharat Ram followed by Africa Star. The pollen of the varieties Folklore and Pusa Ajay failed to germinate in all the five treatments, neither did they set hip. Higher hip set was recorded with pollination of varieties Africa Star and Dr Bharat Ram. The treatment T2 (15% sucrose) recorded the highest percent of pollen germination compared to other treatments used. Pollen diameter was highest (51.22 μm) in variety Africa Star followed by Dr Bharat Ram (50.21 μm), while it was lowest in Pusa Ajay (25.25 μm). Pollen viability, in vitro pollen germination and hip set were positively correlated with pollen diameter. The varieties Africa Star and Dr Bharat Ram were found to be the best pollen donor among the varieties used for screening. Pollen viability percent and pollen diameter were found to be the best parameters for ascertaining the pollen fertility.