Isolated Microspore Culture In Carrot (Daucus Carota L.)

The effects of genotype and cold pretreatment on carrot microspore culture were evaluated, the developing modes of microspores were cytological analyzed, and polidy of the regenerated plants were tested.Fifty seven accessions were used for carrot isolated microspores culture, and 26 responded. There were significant differences about the embryoids and calli occur between genotypes. The production of 70198 was higher with 10.56 embryoids per dish, while 70Q75,90121,90C17,90D25,90E12 and 900Q1 produced less than 1 embryoids per dish. 70Q78, 90203 and 90W78 formed 39.00, 21.00, 21.67 calli per dish.There was significant difference about the average ratio of four deals, and the better was that of the control. The average ratio of control was 13.62%, while only 7.55%,6.96%,0.78% with 1, 2, 3 d cold treatment respectively. To some accessions, cold pretreatment was positive for induction of embryoids or calli, such as 900C2 with 35.71% under 2 days cold pretreatment but only 5.88% at the control.Cytology observation showed that microspores with thin wall, size elongating, and large vacuole would develop into embryos. Firstly they latitude split, arranged in series and connected tightly each other. While the microspores expanding like globe shape, splitting and connecting loosely would grow up to calli.One hundred and thirty-seven plantlets from three accessions were used to analyze ploidy using flow cytometry, and there were 68.6% haploid, 29.9% diploid, and 1.5% triploid. There were significant differences about the leaf color intensity, size among the haploid, DH and triploid. DH was bigger than haploid while smaller triploid. There were differences among regenerated plants lines of the same accession, such as 80Q54.