Changnienia amoena Chien is a monotypic species and endemic to China, and was listed on the Chinese Red Book in 1992. The species was once abundant but has become rare and endangered in recent years because of the hab...Changnienia amoena Chien is a monotypic species and endemic to China, and was listed on the Chinese Red Book in 1992. The species was once abundant but has become rare and endangered in recent years because of the habitat fragmentation and unduly commercial collections. Previous observation showed that this species has very low and even no fruit set, and the pollinators are not observed before this report. The present observation was conducted at the Shennongjia, Hubei Province during the spring of 2002. The results showed that Bombus (Diversobombus) trifasciatus Smith, B. imitator Pittion and one species of Apis visited the flowers of the orchid, but only B. tritasciatus could carry pollinaria on its body and was the legitimate pollinators of C amoena. During 113 h of observation, only nine visitations were recorded. The bumblebees mainly appeared during 12:00-15:00 during the day. Bumblebees stayed in a flower only a few seconds and never more than ten seconds. The flowers would persist in fresh for about three weeks when they were not pollinated, but 3 or 4 d after pollinated, the pollinated flowers underwent a series of color and morphological changes including stalk elongation and ovary swelling. Therefore, stalk elongation can be considered an index of fruits set. Artificial pollination indicated that C amoena is a highly self-compatible and outcrossing species, but dependent on pollinators for fruit set. Based on the field observations, we concluded that pollination system of C amoena is deceptive. The fruit set in nature is not very low (26.98% on average) compared to other deceptive orchids, which may be related to small population sizes. The number of pollinia removal is much higher than that of fruit set, indicating that there are some degrees of pollinia wasting in C amoena.展开更多
An efficient procedure is outlined for rapid and mass propagation through in vitro culture of pseudobulbs collected in different seasons of an endangered orchid, Changnienia amoena Chien. Axillary buds formed on intac...An efficient procedure is outlined for rapid and mass propagation through in vitro culture of pseudobulbs collected in different seasons of an endangered orchid, Changnienia amoena Chien. Axillary buds formed on intact pseudobulbs (collected in April) after a 12-week incubation on half-strength Murashige and Skoog (1/2 MS) medium supplemented with 1 mg L-1 N6-benzyl- adenine (6-BA), 0.5 mg L-1 α-naphthaleneacetic acid (NAA), 100 ml L-1 coconut water and 0.8 g L-1 polyvinylpyrrolidone; no buds were observed on segmentalized pseudobulbs incubated on the same medium. The axillary buds obtained from pseudobulbs growing in the natural habitat in June were detached and incubated for 7 weeks on the same medium leading to 1.4 shoot buds per explant. With repeated subculturing of the shoots on 1/2 MS medium supplemented with 2 mg L-1 6-BA and 0.5 mg L-1 NAA, a mean of 3.3 shoot buds per explant were observed on successive shoot cultures. A mean of 4.5 roots per shoot were induced on the optimal root induction medium with 1/2 MS medium plus 1.0 mg L-1 NAA and 0.1 mg L-1 6-BA and the highest rooting per centage was 88.9%. Plantlets 4-5 cm in height were transplanted into pots containing a 1:1 humus and sand mixture and grown for 7 weeks in a greenhouse before being transferred to the field. The survival rate of these transplants was about 75% after two months of growth in the wild.展开更多
文摘Changnienia amoena Chien is a monotypic species and endemic to China, and was listed on the Chinese Red Book in 1992. The species was once abundant but has become rare and endangered in recent years because of the habitat fragmentation and unduly commercial collections. Previous observation showed that this species has very low and even no fruit set, and the pollinators are not observed before this report. The present observation was conducted at the Shennongjia, Hubei Province during the spring of 2002. The results showed that Bombus (Diversobombus) trifasciatus Smith, B. imitator Pittion and one species of Apis visited the flowers of the orchid, but only B. tritasciatus could carry pollinaria on its body and was the legitimate pollinators of C amoena. During 113 h of observation, only nine visitations were recorded. The bumblebees mainly appeared during 12:00-15:00 during the day. Bumblebees stayed in a flower only a few seconds and never more than ten seconds. The flowers would persist in fresh for about three weeks when they were not pollinated, but 3 or 4 d after pollinated, the pollinated flowers underwent a series of color and morphological changes including stalk elongation and ovary swelling. Therefore, stalk elongation can be considered an index of fruits set. Artificial pollination indicated that C amoena is a highly self-compatible and outcrossing species, but dependent on pollinators for fruit set. Based on the field observations, we concluded that pollination system of C amoena is deceptive. The fruit set in nature is not very low (26.98% on average) compared to other deceptive orchids, which may be related to small population sizes. The number of pollinia removal is much higher than that of fruit set, indicating that there are some degrees of pollinia wasting in C amoena.
基金supported by Zhejiang Provincial Natural Science Foundation (Y507195)the National Key Project of Scientific and Technical Sup-porting Programs Funded by Ministry of Science & Technology of China (2008BAC39B05)
文摘An efficient procedure is outlined for rapid and mass propagation through in vitro culture of pseudobulbs collected in different seasons of an endangered orchid, Changnienia amoena Chien. Axillary buds formed on intact pseudobulbs (collected in April) after a 12-week incubation on half-strength Murashige and Skoog (1/2 MS) medium supplemented with 1 mg L-1 N6-benzyl- adenine (6-BA), 0.5 mg L-1 α-naphthaleneacetic acid (NAA), 100 ml L-1 coconut water and 0.8 g L-1 polyvinylpyrrolidone; no buds were observed on segmentalized pseudobulbs incubated on the same medium. The axillary buds obtained from pseudobulbs growing in the natural habitat in June were detached and incubated for 7 weeks on the same medium leading to 1.4 shoot buds per explant. With repeated subculturing of the shoots on 1/2 MS medium supplemented with 2 mg L-1 6-BA and 0.5 mg L-1 NAA, a mean of 3.3 shoot buds per explant were observed on successive shoot cultures. A mean of 4.5 roots per shoot were induced on the optimal root induction medium with 1/2 MS medium plus 1.0 mg L-1 NAA and 0.1 mg L-1 6-BA and the highest rooting per centage was 88.9%. Plantlets 4-5 cm in height were transplanted into pots containing a 1:1 humus and sand mixture and grown for 7 weeks in a greenhouse before being transferred to the field. The survival rate of these transplants was about 75% after two months of growth in the wild.
