Study On Occurrence Mechanism And Control Techniques Of Persistent Calyx Fruit And Roughbark Fruit Of Korla Fragrant Pear

This study conducted at the orchard in Saydong horticultural farm of Bayingulin Mongolian Autonomous Prefecture and Shanghu town of Korla city,20years old Korla fragrant pear trees were used as experimental materials. This paper mainly studied:difference on fruit quality between Korla fragrant dropping calyx and persistent calyx normal pear, dropping calyx and persistent calyx roughbark pear; effect of GA3, PP333and orchard area temperature on plant hormones in Korla fragrant pear and dropping of calyx within flower stage:effect of compound reagent "M"’and PBO on dropping of calyx and fruit quality of Korla fragrant pear; and effect of calcium, boron and salicylic acid on controlling of roughbark pear and inhibiting of lignin synthesize key enzymes activity within Korla fragrant pear development process. By doing comprehensive analysis on over indices to get follows conclusion:1. Normal pears (dropping calyx and persistent calyx pear) were characterized with low firmness and low tannin contant compare to the roughbark pear (dropping calyx and persistent calyx pear). There was no any significant difference on tannin content and fruit firmness between dropping calyx and persistent calyx pear. The content of anthocyanin and chlorophyll in dropping calyx normal pear were higher than in persistent calyx pear, dropping calyx and persistent calyx pear, but its carotenoid content was lowest. The total content of sugar, sucrose, soluble solid, Vc content and solid-acid ratio in the flesh of the dropping calyx normal pear were significantly higher than dropping calyx and persistent calyx roughbark pear; the content of glucose and fructose in the flesh of dropping calyx normal pear were significantly higher than dropping calyx and persistent calyx roughbark pear, but there was no any significant difference compared with persistent calyx normal pear, the content of glucose and fructose in the flesh of persistent calyx roughbark pear were lowest in all types of pear. The order on better fruit quality of four fruit types showed that:normal pear in dropping calyx> normal pear persistent calyx> roughbark pear in dropping calyx> roughbark pear in persistent calyx.2. Korla fragrant pear in full-bloom stage was encounrered low temperature in2010th year, but the area temperature in next year (2011th) within same time kept higher than over20℃. Compared with2011th year, dropping calyx rate of Korla fragrant pear was higher; endogenous GA3content was lower; and ABA content was higher. Spraying of PP333in full-bloom stage could enhance dropping calyx rate by decrease GA3content, increase ABA content, effect of GA3was inverse. Therefore, low temperature within full-bloom stage and spraying of PP333could effectively accilrative dropping of Korla fragrant pear calyx by decreased GA3content, increased ABA content.3. After being treated with M1, fruit set rate, calyx dropping rate, content of chlorophyll and anthocyanin of Korla fragrant pear was higher than other treatment M2、PBO and CK. To compare on contents of sugar, Vc, tannin, soluble solid, titration acid and solid-acid ratio of all treatments, M1and PBO had the best effect on improving of those indices. In a word, at full-bloom stage treated with compound reagent "M1" have a best accelerative effect on fruit set rate, dropping calyx rate and improvement of fruit quality.4. Spraying of600times calcium (calcium nitrate),1000times calcium boron mixture and500times calcium boron mixture (500times calcium nitrate+500times boric acid) have best effect on preventing to Korla fragrant roughbark pear, all of those treatment could effectively inhibited to the lignin synthesize key enzymes activity and kept the lignin content within all fruit development process, have a popularization value on controlling of roughbark fruit of Korla fragrant pear...