| Cymbidium hybridum is a most popular potted flower in the New Year market, which cultivated and produced throughout our nation wide. To meet the temperature requirements of Cymbidium normal growth and development, greenhouse Cymbidium cultivation generally utilize heating in the winter and cooling in the summer. It’s very significant to select some cold or heat resistance varieties for the modern greenhouse production in energy-saving and emission reduction. The paper choose Cymbidium varieties;such as C.’Golden Yellow’、C.Lovely moon’Croscent’, etc. as the test materials to10/0℃cold and40/30℃heat stress. Combined with a series of ornamental morphological index:color, inflorescence length. etc, using AHP evaluation method to establish a integrated value comprehensive evaluation system. The laboratory selecting system for the temperature resistance varieties was established furthermore.The main conclusions are as follows:1. The results of eight Cymbidium varieties under10/0℃Low temperature treatment showed:With the extension of stress time, Fv/Fm、 Fresh weight and dry weight decreased, F0、MDA、electric conductivity and soluble protein content increased, while soluble sugar content dropped after the first rise. C.’Fuku Musume’ MDA、electric conductivity and F0increased significantly after high temperature stress, Fv/Fm decreased rapidly but difficult to recover when the temperature returned, soluble sugar and soluble protein content lower than other varieties conspicuously; C.’Golden Yellow’.. C.’Buddy Mark’n C.’Favored’ MDAn electric conductivity and F0increased in a small scale, while high in soluble sugar and soluble protein content, Fv/Fm decreased in small scale and recovered quickly as the temperature returned; all the parameter of other varieties changed between them.2. The correlation analyses among the data of Fv/Fm, F0, electric conductivity, MDA, Soluble sugar and soluble protein content showed that highly significant correlation. The correlation coefficient between Fv/Fm and chilling injury index was-0.944, so Fv/Fm can be used as a reliable indicator to reflect the cold resistance of different Cymbidium varieties. All data indicated that the difference of hardiness of8varieties was significant, and the hardiness from high to low were:C.’Golden Yellow’> C.’Lihi Tabidachi’、C.’Buddy Mark’、C. Lovely moon’Croscent’、C.’Honey Heart’, C. Royal Red Princess’Nobuko’、C. Plair’Days Memory’、C.’FukuMusume’.3. The results of eight Cymbidium varieties under40/30℃high temperature treatment showed: chlorophyll a、Chlorophyll b、Fv/Fm decreased with the extension of treatment time; C.’Golden Yellow’ Fv/Fm decreased in small scale and recovered to90%of the initial value quickly as the temperature returned, which had the strongest hardiness; C.’Fuku Musume’ and C.Great Katy’Chartreuse’had the worst hardiness, Fv/Fm decreased significantly but difficult to recover when the temperature returned; Fv/Fm and heat injury index was significantly associated that can be used as a reliable indicator to screen heat-resistant varieties of Cymbidium. The results indicated that the difference of heat resistance of eight varieties from high to low were:C.’Golden Yellow’、C.’Buddy Mark’、C.Wakakusa’Dargu’、 C.New Torino’UFO color’、C. Royal Red Princess’Nobuko’、C.Lovely moon’Croscent’、C.Great Katy’Chartreuse’、C.’Fuku Musume’.4. Eight Cymbidium varieties were studied and evaluated on the comprehensive value, superior hardiness varieties were:C.’Golden Yellow’>C.’Buddy Mark’> C.’Lihi Tabidachi’>C. Plair’Days Memory’>C. Lovely moon’Croscent’> C.’Honey Heart’>C. Royal Red Princess’Nobuko’> C.’Fuku Musume’;superior heat resistance varieties were:C.Wakakusa’Dargu’>C.’Golden Yellow’> C.’Buddy Mark’> CNew Torino’UFO color’> C. Royal Red Princess’Nobuko’> CLovely moon’Croscent’> C.’Fuku Musume’> C.Great Katy’Chartreuse’.5. Established a hardiness and heat tolerance laboratory filtering system for Cymbidium varieties: taking the small seedlings of8x8cm pot as a standard material, under1-5days10/0℃low temperature or3-9days40/30℃high temperature stress in the artificial climate chamber, calculate chilling or heat injury index by the change of Fv/Fm. those varieties whose Fv/Fm decrease slowly or recovery rapidly have strong resistance,Screen hardiness and heat superior varieties were based on morphological characteristics、resistance and comprehensive evaluation scores by means of AHP.6.Four Cymbidium varieties were applied to illustrate the tolerance laboratory filtering system,the comprehensive value of the hardiness varieties from high to low were:’188-3’、CNew Torino’UFO color’、C.’Kassai’、C.Great Katy’Chartreuse’; the comprehensive value of the heat resistance varieties from high to low were:C.’Lihi Tabidachi’、C.’Honey Heart’、C.’Kassai’、C.’Yang Gui Fei’... |
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