Pollination and Fertilization Capacity of in vitro Treated Male Date Palm (Phoenix dactylifera L.) Strands of Spathes Collected Before and After Cracking

Abstract

This study was conducted to investigate the reproductive attributes that affect pollination and fertilization capacity of male date palm (Phoenix dactylifera L.) strands of spathes collected after and before cracking, and treated in vivo. Spathes were collected from three trees, one, two, three and four days before, and just after, cracking. Strands from each spathe were examined fresh and after drying and after incubated in distilled water (DW) or in warm acidified water (WAW) ( 42 ±2oC, pH5 ± 0.5). The results revealed that the strands from the spathes collected after, and one day before, cracking and incubated in WAW exhibited 100% open flowers and dehiscent anthers. Significantly less percent open flowers and dehiscent anthers were on the strands from the spathes collected two days, than those induced by the corresponding in vitro treatments of the strands from the spathes collected one day, before cracking. Some strands from the spathes collected three days before cracking were with open flowers and dehiscent anthers when incubated in WAW. The strands from the spathes collected four days before cracking were devoid of open flowers and dehiscent anthers. More than 80% of pollen grains released from dehiscent anthers were viable. Thus, collecting male date palm spathes within 24, and probably 48, hours, before cracking and incubating them in WAW would improve their pollination and fertilization capacity, reducing the number of times needed to climb male date palm trees and saving the otherwise dispersed pollen grains.