Articles
PRELIMINAR EVALUATION OF ACCLIMATIZATION SYSTEMS IN CHLORAEA CRISPA LIND. (ORCHIDACEAE) FROM INOCULATED SEEDS
Article number
748_17
Pages
147 – 150
Language
English
Abstract
Chloraea crispa is an endemic terrestrial orchid with good characteristics as a cut-flower like length stem, number of flowers by stem and long vase life.
This species has small seeds that germinate associated to Rhizoctonia. In a program of genetic improvement of Chloraea crispa, it is necessary to develop a germination protocol with a high efficiency and low cost.
We have obtained protocorms from seeds sowed in vitro in oatmeal agar medium inoculated with Rhizoctonia. The present study describes the establishment under ex vitro conditions of orchid plantlets.
In the first trial, we evaluated two states of protocorms development (II and III) for transplant and three acclimatization systems.
The first system includes two weeks in a bioclimatic chamber with 16 to 22ºC and 16 light hours; then the plantlets were kept two weeks at environmental temperature (10 to 25ºC) to finish in a shady place.
The second system was two weeks in a bioclimatic chamber and later the plantlets were transferred to environmental temperature.
Finally, in the third system consisted of maintaing the plantlets two weeks at environmental temperature and then in a shady place.
Based on the results of the first trial, we designed a second trial where the substrate (organic soil with perlite, 1:1) was replaced with a substrate of agar (8 g L-1) / oats (25 g L-1) with a thin layer of sand with two sterilization methods.
Protocorms on the state III were used.
In the first trial, the second acclimatization system allowed a survival for a period of 90 days in plantlets transplanted in both states, however, only plantlets of state III produced chlorophyll.
It was proposed that the state III is the optimum for transplant.
The protocorms did not form roots and its nutrition depended of the symbiotic relation with Rhizoctonia, which cannot keep this symbiotic relation if the fungus is unable to reach a carbon source.
In the second trial at 120 days, we observed 24 to 28% of survival with plants 1.5 to 2.0 centimetre high and formed at least one leaf, without significant difference between sterilization methods.
The second trial showed better response than first trial possibly due to the transplant season (March) which is more adequate for the species; however, the results could be improved and it is necessary to develop new trials in order to obtain a survival percentage higher than 70%.
This species has small seeds that germinate associated to Rhizoctonia. In a program of genetic improvement of Chloraea crispa, it is necessary to develop a germination protocol with a high efficiency and low cost.
We have obtained protocorms from seeds sowed in vitro in oatmeal agar medium inoculated with Rhizoctonia. The present study describes the establishment under ex vitro conditions of orchid plantlets.
In the first trial, we evaluated two states of protocorms development (II and III) for transplant and three acclimatization systems.
The first system includes two weeks in a bioclimatic chamber with 16 to 22ºC and 16 light hours; then the plantlets were kept two weeks at environmental temperature (10 to 25ºC) to finish in a shady place.
The second system was two weeks in a bioclimatic chamber and later the plantlets were transferred to environmental temperature.
Finally, in the third system consisted of maintaing the plantlets two weeks at environmental temperature and then in a shady place.
Based on the results of the first trial, we designed a second trial where the substrate (organic soil with perlite, 1:1) was replaced with a substrate of agar (8 g L-1) / oats (25 g L-1) with a thin layer of sand with two sterilization methods.
Protocorms on the state III were used.
In the first trial, the second acclimatization system allowed a survival for a period of 90 days in plantlets transplanted in both states, however, only plantlets of state III produced chlorophyll.
It was proposed that the state III is the optimum for transplant.
The protocorms did not form roots and its nutrition depended of the symbiotic relation with Rhizoctonia, which cannot keep this symbiotic relation if the fungus is unable to reach a carbon source.
In the second trial at 120 days, we observed 24 to 28% of survival with plants 1.5 to 2.0 centimetre high and formed at least one leaf, without significant difference between sterilization methods.
The second trial showed better response than first trial possibly due to the transplant season (March) which is more adequate for the species; however, the results could be improved and it is necessary to develop new trials in order to obtain a survival percentage higher than 70%.
Publication
Authors
G. Verdugo, C. Mesa, M. Cisternas, X. Calderón
Keywords
Chilean orchid, ex vitro conditions, symbiotic germination, geophyte
Online Articles (36)