Phalaenopsis Polyploidy Breeding Based On The Induction Of 2n Gametes And Protocorm

Chromosome doubling play an important part to better Phalaenopsis horticultural traits,such as flower color and size,plant height,stress resistance and so on.Polyploid orchids usually have stronger stems,thicker leaves,larger and brighter flowers and stronger adaptability to stressful environmental conditions.This research mainly focused on the Phalaenopsis chromosome doubling technology which conclude observation of the meiosis process of Phalaenopsis microspore mother cells,the induction of2 n pollen of Phalaenopsis and the induction of seed and protocorm in vitro doubling.The main results of this article are as follows:1.The meiosis period of Phalaenopsis has a correlation with the flower bud diameter.The meiosis period of the Phalaenopsis equestris,Phalaenopsis equestris var.Coerule,Phalaenopsis Anna-Larati soekard,Phalaenopsis Tzu Chiang Sapphire,Phalaenopsis Queen Beer ‘Red Sky’,Phalaenopsis Purple Crystal pollen mother cells(PMCs)was observed,and the results showed that the meiosis period was related to the flower bud length.Different Phalaenopsis meiosis periods last from 4.2 to 14 days.2.Phalaenopsis can produces natural 2n pollen,and a colchicine protocol for Phalaenopsis 2n pollen has been established.Depending on species,2n male gamete formation frequencies varied from0.68% to 1.78%.Finally,we induced 2n pollen of Phalaenopsis equestris in different meiosis period with different colchicine concentration for 3 days.The most effective treatment to obtain 2n pollen is cover 0.05% colchicine to flower buds in the leptotene to zygotene stage for 3 days,and the induction rate can reach to 10.04%.3.The process of co-cultivation of colchicine to induce the protocorm of Phalaenopsis ‘H-03’ to obtain polyploid plants was established.In order to explore the effect of colchicine on chromosome polyploidization of Phalaenopsis,protocorms of Phalaenopsis ‘H-03’(2n=2x=38)were used as the materials to induce polyploid by colchicine treatment with mixed culture method in this study.The results showed that the most efficient condition for inducing mutant plants was treated with 0.05%colchicine for 15 d,which resulted in about 30.00% surviving plants and 50.00% of mutation plants.Compared with the control plant,the mutant plant showed dwarfed,with dark green,rough surface,broad leaves,short or round leaves.Some mutant plants also had abnormal and twisted leaves.The observation of stomata showed that the shape of stomata were round,the number of stomata per unit area decreased and the size of stomata are larger.The length and width of the stomata increased by76.45% and 38.99%,respectively.The results of this study provide with a theoretical basis for breeding new varieties of Phalaenopsis.4.The process of obtaining polyploid plants from Phalaenopsis zhejiangensis seeds induced by colchicine was established.Using Phalaenopsis zhejiangensis seeds as materials,the in vitro colchicine treatment methods of on solid medium and in liquid medium were used to induce polyploid plants.The results showed that the colchicine induction effect of in liquid medium for 5 days and colchicine concentration of 0.2% for 1 day was the best.The survival rate and induction rate of tetraploid and chimera were 6.41%,27.75%,and 34.84%.There are more tetraploid plants than that inducing protocorm.