Studies On Cross Breeding And Capsule Abortion Of Cymbidium Hybridum And Chinese Cymbidium

The research materials were based on26cultivars of Cymbidium hybridum imported from YiJinfarm in Yuxi City of Yunnan Province, about320cultivars of Chinese Cymbidium imported fromZhejiang Shaoxing, Fuyang, Tonglu, Tiantai and Chendu in Sichuan Province, and so on. The place oftest in Landscape Architecture greenhouse, gardens institute laboratory and intelligent laboratorybuilding of Zhejiang Agriculture and Forestry University. The most studies focused on three aspects:The first was studies on pollen vitality and stigma receptivity of Cymbidium hybridum and ChineseCymbidium; the second was studies on cross breeding of Cymbidium hybridum and ChineseCymbidium, Including self-crosses, direct crosses and reciprocal crosses between different varieties ofintraspecific and interspecific tests; observed ovary growth developmental dynamics after pollinationbehavior. The third was studies on Cymbidium hybridum abortion capsule phenomena includingdifferent nutritional elements of capsule growth; different growth environment of the ovary afterpollination; the relationship between capsule and embryonic with abortion phenomena. The mainresults are indicated as follows:1. The pollen viability test proved: TTC staining method is the most intuitive and effective way toobserve the pollen viability of Cymbidium hybridum and Chinese Cymbidium. Cymbidium hybridumduring25~35d have the strongest pollen viability, during15~25d Chinese Cymbidium have the bestpollen viability. Throughout the florescence, stigma of Cymbidium hybridum and Chinese Cymbidiumcan be granted, The stigma of Cymbidium hybridum within20d to40d reach highest, ChineseCymbidium about15d to25d can be granted strengthen. The combination of cross breeding testsshowed that pollen viability and the stigma receptivity strength of pollination success rate havesignificantly related on pollen vitality and stigma receptivity, the stronger vitality and receptivity thehigher success rate of cross breeding.2. Cymbidium Cymbidium and Chinese Cymbidium cross breeding test proved: ChineseCymbidium pollination success rate was significantly higher than Cymbidium Cymbidium pollinationsuccess rate. Self-crosses test of flowers seed rate is significantly higher than the direct and reciprocalcrosses test; the intraspecific hybridization seed rate is significantly higher than the interspecifichybridization seed; pollination success rate of different varieties was slight.3. The studies on Chinese Cymbidium and Cymbidium hybridum capsule growth and developmentdynamic have shown that: the capsule growing is the “single S” shaped. Mature capsule size of Cymbidium hybridum is generally greater than the capsule of Chinese Cymbidium. Cymbidiumcapsule fall off have two peak periods: Chinese Cymbidium capsule drop peak during25~35d afterpollination and90~150d. Cymbidium hybridum capsule drop at the peak of45~60d after pollinationand120~170d.The two times fall off peak periods respectively corresponded to the process offertilization and embryo development.4. Abortion capsule phenomenon outstanding on Cymbidium hybridum, by the capsule nutritionalelements analysis showed:“Hyponex (N: P: K=1:3:2)1000ppm” processing was the most suitableratio of capsule growing, lack of nutritional elements is one of the reasons why cause abortionphenomena. Secondly, Orchids optimum growing temperature for about10~25℃, higher or lowertemperature all impact on their growth, therefore, different growth conditions can also cause abortion.Finally, compared with the embryo of normal mature and abortion capsule proved mature capsulehave development completely, significant embryo, the embryo do not exist in abortion capsule.More than two years of Cymbidium hybridum and Chinese Cymbidium cross breeding trials,indicators and conclusions about their pollen viability, stigma receptivity analysis, parents’ selection,cross breeding, ovary observation, abortion capsule and other related links. It has great significancefor carry out further breeding work of Cymbidium hybridum and Chinese Cymbidium.