Effects of Orchid Mycorrhizal Fungi with Plant Growth Substances on the Growth and Development of Paphiopedilum spp.

• Main Authors: Chun-Cheng Chen, 陳俊成
• Other Authors: Chi-Ning Chang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/12276304171319355950

碩士 === 國立臺灣大學 === 園藝學研究所 === 93 === Abstract After inoculating one of five Rhizoctonia orchid mycorrhizal fungi(OMF) : RO1 R02 R04 R13 R14 with two cultivars of Paphiopedilum seedlings for 4 months ,we investigated the effects of OMF on the growth of were investigated. Resent showed that in Alma Gavaert ''Goto'' x Maudiae ''Silverado'' AM/AOS, inoculation with R02 increased the leaf length, fresh weight, and the survival rate 100% of seedlings. In another cultivar ,Alma Gavaert ''HB'' x Janet Kunkle ''Grace Hsinying, inoculatioin with R13 increased leaf length and inoculation with R02 and R14 increased the fresh weight of seedlings. It showed that inoculatioin with OMF R02、R13、R14 enhanced the growth and survival rate of Paphiopedilum seedlings. The OMFs in this experiment belonged to Rhizoctonia spp.. It was observed that hypha invaded into orchids root mainly throught root hair cell, and then penetrated throught velamen, exodermis, and then cortex region, but would not reach stele。Hypha formed pelotons in cortex cells and infected neighboring cells by single hypha. Confocal microscop could show 3-D image of pelotons. It was concluded that the model of symbiosis between Rhizoctonia and root of Paphiopedilum is tolypophagy. Effect of plant growth substance on Paphiopedilum showed that inoculation of R02 then applied of Aminosong could increase leaf number and fresh weight of Paphiopedilum delenatii. This treatment increased 3.9 g in fresh weight after four months of treatment control. Aminosong treatment could increased CMR and the length of the first and the second leaf of Paphiopedilum delenatii. Inoculation with R04 and then applied Aminosong or choline chloride increased leaf number. In Paphiopedilum hybrida Impulse ''376-1'' x fairrieanum ''Bounds'', inoculation with R02 paired with use of Lysine＃24 significantly increased leaf number, length of the second leaf and fresh weight significantly. Inoculation with R02 paired with Aminosong also significantly increased leaf number, length of the first leaf, CMR, and fresh weight in this cultivar. In another Paphiopedilum hybrida Alma Gavaert ''Goto'' x Maudiae ''Silverado'' AM/AOS, inoculation with R02 alone or inoculation with R01 or R02 plus the application of Lysine＃24 improved fresh weight substantially them the control. Inoculation with R02 and applied with Aminosong increased length of the second leaf and CMR significantly in this cultivar. Spraying GA3 70 ppm or GA3 70 ppm + BA 30 ppm improved flower stalk emergence on Paphiopedilum Maudiae type, but the flowers with GA3 treatment formed abnormal flower, such as rolled in sepal and petal, reduced in width of petal and twisted in stalk, which lead to loss of ornamental value. GA3 and BA co-treatment also lead to the same result. Only when spraying 30 ppm BA on Paphiopedilum Maudiae type, flowers opened naturally and the length and width of flower were both 1cm longer than the control. This suggested that BA significantly increased flower size of Paphiopedilum Maudiae type. Inoculating with OMF could not reduce flower abnormality as caused by GA3 treatment. Spraying GA3 70 ppm + BA 30 ppm on Paphiopedilum hybrida before the appearance of flower bud would not caused flower stalk emergence at all. GA3 can induce 8% of flower stalk emergence, but BA treatment could not induce flower stalk formation of slipper orchids. Therefore it was concluded that the main function of BA possibly was to induce the flower stalk emergence for those plants already had flower buds. Reducing the GA3 concentration to 30 ppm or 10ppm also produced abnormal flowers. Therefore it was suggested that spraying BA on Paphiopedilum Maudiae type is beneficial to flowering and improving flower quality of slipper orchids. In contrast, GA3 was not recommended.