Study On Propagation Biology And Compatibility Of Interspecific Hybridization In Tulipa Spp.

Tulipa L.,one of the most famous bulb flowers in the world,was endowed with highly ornamental value and economy value.The cultivation of tulip began more than 400 years ago in the world.In recent years,tulip industry got rapid development with the development of economy in our country,the demand of tulip bulbs was increasing year by year,but the new cultivar of our own intellectual property have not been cultivated that lead to the bulbs supply dependence on imported from other country seriously.Meanwhile,the bulb degraded seriously in cultivated period,so we need to buy the bulbs every year,that restricts seriously the development of tulip industry in our country.At present,all most research focused on biological characteristics,physiological change,cultivation techniques,prevention and control of diseases and insect pests of tulip,however,there was little research on tulip breeding.Wild tulip resources were very rich in our country and have been reported 17 currently in China,including more than 10%wild tulips resources of the whole world.Wild resources have significant importance in breeding new cultivars,wild Tulipa species have many favourable horticultural characteristics,such as various colours,strong disease resistance and good adaptability.Our own wild tulip resources should be made full use of in introduction and interspecific hybridization for realizing the sustainable development of tulip industry in China.Therefore investigation and collection and evaluation of tulip resources would provides some academic bases and references for the application of wild tulip,the research of the wild tulip reproductive biology would take the advantages in the breeding selection,domestication and characteristic improvement of tulip resources in China and get some plant materials with excellent ornamental traits for using in the urban greening.Using unique tulip resources in our country,engage in distant hybridization between the varieties for provide a reference for improving characteristics of modern tulip cultivars using wild species native to China.The main results were as follows:Total 83 accessions were collected from Xinjiang,Liaoning and several other provinces.Their distribution,collection,classification and evaluation were described.According to morphological characteristics,they were classified into eight species,which included T.sinkiangensis Z.M.Mao,T.altaica Pall.ex Spreng.,T.iliensis Regel,T.heterophylla Baker,T.buhseana Boiss.,T.thianschanica Regel,T.schrenkii Regel and T.edulis(Miq.)Baker.The analytic hierarchy process(AHP)was used to evaluate the ornamental value,utilization potential and ecological adaptability of the eight identified species.The results showed that T.iliensis,T.buhseana and T.thianschanica had better ornamental value and utilization potential than any other species and they were divided rank ?,T.sinkiangensis and T.altaica were divided rank ?,T.schrenkii and T.edulis were rank ? and T.heterophylla was rank IV.The distribution,collection,classification,and evaluation of wild Tzlipa species could be helpful in creating novel tulip germplasms in China.The bulbs of eight tulip species were used for introduction in Shenyang,there were some differences when cultivated in different environmental conditions and different soil,the results showed that:wild tulip had a remarkable ability to adapt to changing environments,that cultivated sccussfully in Shenyang,they maintained the original biological characteristics in artificial reproduction.Humus was the best soil for wild tulip cultivation.The result of bulb propagation with bulbs showed that one or more long fleshy stolons formed horizontally or vertically at the basal plate of the mother bulbs,new bulblets(dropper)appeared at the top of each fleshy stolon,and the mother bulbs eventually disappeared.There were 1-2 propagated bulbs produced in T.edulis and there was no one in other tulip species.So the bulbs were not suitable for rapid propagation of wild tulip.The seeds of T.altaica,T.schrenkii and T.edulis were used in germination experiment for researching on seed germination characteristics and hormone content of wild tulips.The results showed that:The seeds of wild tulip absorbing water rapidly,seed coat was not the main cause of wild tulip seed dormancy.The highest germination rate of all there tulip species were 76%,78%and 90%when storage for 90 d under 5? and 90%relative humidity and the hormone content changed greatly.The germination time of seed shorten and the hormone content changed significantly by GA3 treatment,the best concentration was 200 mg/L.The highest germination rate were 53.5%,62.1%and 55.7%when cultivated in peat and fine sand of there tulip species.The bulbs,leaves and stalks of T.edulis,T.iliensis and T.schrenkii were used as explants for research to the influencing factors in vitro culture and browning of the wild tulip,to explore the rapid propagation methods of wild tulip.The results showed that the lowest contamination rate of explant were 14.0%,9.5%and 8.2%when disinfected by 0.1%Hgcl2 for 10 min,but the rate of browning was rasied.Callus induction and differentiation of T.edulis were better than other two species and best medium was MS+TDZ 2.0 mg/L+NAA 0.5 mg/L+BA1.0 mg/L,the rate induction and differentiation were 67.4%and 72.4%and the rate of browning was lowest.The rate induction and differentiation of T.iliensis and T.schrenkii were very low,the browning rate of stems was highest.The media with Vc can reduced browning rate and raised rate of induction of explants,the best concentration was 200 mg/L.some more experiment on wild tulips need to be done for establish the tulip rapid propagation system.Judith Leyster,World's Favorite,Purple Cloud,T.edulis,T.sinkiangensi and T.tianschanica were used to distant hybridization,the results showed that:The best medium of pollen germination was 1/2MS+10%Sucrose+0.5%Agar+2 mg/LBoricacid+2 mg/L Ca(NO3)2,germination rate of three tulip species were 32.7%,29.5%and 27.9%.The rate of the rate of pollen germination was highest when storage for 10 d under 25?,fresh pollen germination was lowest,the rate of pollen germination decreased gradually with the increase of storage time.The stigma receptivity of all parents at 1 d before blooming,the stigma receptivity decreased gradually with the blooming time increased.The rate of fruits setting was highest of hybrid combinations Ziyun×T.edulis was 62.2%,when pollinated 1 d before blooming,the rate of fruits setting decreased gradually with the blooming time increased.Some seeds embryo were got from reciprocal crosses of Judith Leyster×T.edulis,Purple Cloud×T.edulis and T.sinkiangensis×Judith Leyster,some seeds embryo were got from Purple Cloud×T.sinkiangensis,Judith Leyster×T thianschanica and World's Favorite×T.sinkiangensis,the seeds from other hybrid combinations had not been formation.The vitality of interspecific hybrid seeds of tulips was high,and the rates of seeds germination and plants survival had no significant difference beween F1 and parents.