巨竹及馬來麻竹之平插繁殖

本研究旨在探討引自馬拉加西Tamatave Tananarive及Fianaratsoa省之巨竹，經平埋雙節插穗所培育出之竹苗，其生長因營養系來源及採穗部位所引致之差異；進而解析不同插穗年齡對巨竹及馬來麻竹之平插苗形質及生物量生長之效應，期能供為此二高經濟價值竹種大量繁殖之基礎。儘管引自三處生態環境迴異之巨竹於本省最初3年之生長表現，具存差異，然取3年生竹稈平插繁殖後，在第1年及第2年之萌發率、成苗量及竹苗生長於營養系間不具差異。取自竹稈2/3處以上頂部之插穗，其稈芽之萌發及苗木生長均劣於取自竹稈中、基部者。中部及基部插穗之生長表現至第2年時始具差異。無論是稈芽萌發率或竹苗生長，均與插穗之直徑或稈肉厚度呈極顯著正相關，基本上，插穗直徑位於4公分以下者，不宜供為繁殖之材料。取1～3年生巨竹及馬來麻竹之中、基部竹稈為插穗時，在經1年後，各稈節所萌生竹欉之乾重，如葉、枝、稈、地下莖及竹根乾重，均可由各欉竹苗數、平均最大苗徑、平均苗高或苗徑精確予以估算，相關係數位於0.77～0.98間；各部位乾重之最適預測式之自變數將因部位而異，其中均以各欉竹苗數及平均最大苗徑為主要之預估參數。就巨竹而言，取自1年生作悍之插穗，其萌發及苗木生長均劣於2～3年生者；苗高及苗徑雖於2及3年生間不具差異，然其萌發率、成苗量及各小區之生物量生產量均以3年生者為高。馬來麻竹亦以1年生插穗之表現為最差，惟2及3年生間之差異並不顯著。由平插法所培育出之竹苗，若造林季節選擇正確，此二竹種之造林成活率可達78～97%，成活竹苗多能於造林2年內，萌發出健壯的幼竹。

關鍵字

無性繁殖；平埋雙節插穗；營養系來源；採穗部位；插穗年齡；生長分析；生物量生産量；成活率

並列摘要

This study were to examine the applicability of asexual propagation by level-buried two-noded culms for two exotic bamboo species with high commercial potential in Taiwan. Two parts of experiments were included in this article. The first section intended to evaluate the effect of both clone-sources and culm position on the propagation performance for Dendrocalamus giganteus. The culm-age effect was analyzed for both D. giganteus and D. asper in the second part. Two-noded segments were taken form 3-year-old culms of three clone-sour ces of D. giganteus from Malagasy Republic. Dividing the culms into three parts equally, the culm cuttings were grouped into three classes based on the position of culm buds. A total of 54 plots were arranged by split-plot design with 6 replications in the first part of experiments. Each plot consisted of 12 segments whose cavities were filled up with water from notches at the internodes. The segments were planted horizontally and coved with soils of 6-10 cm in thickness at early March. For D. giganteus and D. asper, two-noded segments were taken from 1-to 3-year-old culms excluding the upper 1/3 portion. A total of 120 plots were arranged by split-plot design with 20 replications for both species. The diameter and height growth were measured for the survived clumps 1 or 2 years after planting. In addition, 30 clumps were randomly selected and excavated for determining the dry weights of leaves, branches, culms, rhizomes, and roots. Equations relating component weights to diameter, height or propagule number per clump were solved by the stepwise repression method. In the first two years after planting, there was no difference in survival ratio and growth performance among three clone-sources of V. giganteus. Significant survival and growth differences were found among cuttings taken from different culm positions. The poorest survival and growth occured for the cuttings obtained from the upper portion of the culms. Differences in growth perfermance between cuttings from middle and lower parts were significant for the young shoots sprouted in the second year, but not for the first year shoots. Both the survival ratio and the growth performance were highly correlated to the diameter of the cuttings where the segments with diameter below 4 am were recommended not to use for the propagation. The component dry weights of clumps could be accurately predicted by the fomative growth parmeters for both V. giganteus and D. asper. The predicted variables incorporated to the final equations were depended on the components and species. In general, the number of propagules and the averaged diameter of the most vigorous propagules were more critical than the averaged diameter and height of all propagules per clump. The effects of the culm age on the development of culm buds were very obvious for both species. The 1-year-old culm cuttings gave the poorest survival and growth. The diameter and height growth of survived clumps had litlte difference between 2-　and 3-year-old culm segments of both species. The survival ratio and the biomass production were higher in the 3-year-old culm segments than the 2-year-old culm segments for D. giganteus. However, no detectable differerences were found between these two age classes for D. aster. The survival ratio which ranged from 78% te 97% were recorded for both species in one or two years after planting in the field. The young culms were vigrously sprouted from the most of survived clumps. In conclusion, segments should he taken from culms excluding the upper 1/3 part when both species are to be propagated asexually by the two-noded level-buried culm cutting method. The optimum culm age is 3 years old with 40% of survival ratio for D. giganteus and 2-3 years old with about 48% of survival ratio for D. asper

並列關鍵字

asexual propagation ； two-noded culm cuttings buried horizontally ； clone-sources ； bud position ； culm age ； growth analysis ； biomass production ； survival ratio

國際替代計量

巨竹及馬來麻竹之平插繁殖

未授權

主題瀏覽