台灣地區劍線蟲Xiphinema elongatum之變異性

Variability within Xiphinema Elongatum Populations in Taiwan

陳殿義(D. Y. Chen) ； 倪蕙芳(H. F. Ni) ； 顏志桓(J. H. Yen) ； 程永雄(Y. H. Cheng) ； 蔡東纂(T. T. Tsay)

《植物病理學會刊》 13卷1期 (2004/03) Pp. 45-60

https://doi.org/10.6649/PPB.200403_13(1).0006

摘要

自1998年起至2002年，以改良式柏門氏漏斗分離法陸續在台灣地區收集10群劍線蟲Xiphinema elongatum。經由雌蟲和其4個齡期幼蟲的形態測量值比較後顯示，除了在百慕達草上所分離的三群雌蟲和其第三及第四齡期幼蟲的體長明顯較長外，各群間其餘的測量值皆相當一致。由每一群的雌蟲及其4個前後齡期幼蟲間的替代齒針和功能性齒針的長度相當接近，以及替代齒針和總口針的長度具有明顯區隔的結果，這10群劍線蟲中都無混雜其他形態類似的劍線蟲種類。X. elongatum（supplements）的釋自為3-4個。在rDNA片段序列的比對結果顯示，3個代表群的群內（Xelo3除外）和群間的ITS-1和ITS-2的序列差異度都極小（0～1.34%），因此具有開發種專一性引子對的可行性。在地理位置上，台灣和中國大陸南部及東南亞地區相當接近，在X. elongatum的形態上也較為相近，而和非洲及南美洲等地區相隔較遠，其形態上的差異則相對明顯，究竟此一變異情形為屬於種內變異的範圍或已是不同種劍線蟲的表線，其解決之道唯有補充其各齡期幼蟲的形態鑑定及rDNA分子序列的比對資料，如此方能對X. elongatum的變異性有充份的認知。

關鍵字

劍線蟲 ； 變異性 ； Xiphinema elongatum ； ribosomal DNA ； rDNA ； ITS-1 ； ITS-2

並列摘要

Ten geographical populations of X. elongatum were collected successively form different area in Taiwna using modified Baermann funnel method during 1998 to 2002. Comapring the morphometrics of female and juveniles among these 10 populations, only the length item of female and the third and fourth stage of juveniles isolated from the Bermuda-grass were longer than the other population, however, the rest of morphometrics were almost identical. Based on the matchable length of the replacement odontostyle and functional odontostyle, and also the evident gap of the replacement odontostyle and total stylet length, between the four successive stages of juveniles and its female in each population, it assured that each population was not mix with other morphologically similar Xiphinema species. Most parts of the morphometrics of male were identical with female, the only difference showed in the tail shape with more variance. The dissimilarity within each population (except for Xelo3) and between the three representative populations (Xelo1, 3, 8) of the rDNA (ITS-1 & ITS-2) sequence alignment was not evident (only from 0 to 1.34%); therefore, it was feasible to develop the species-specific primers. Taiwan, the southeast par of Mainland China, and the Southeast Asia were geographically close, the morphometrics of X. elongatum, according to the worldwide reported data, of these areas were more similar to each other than to that of X. elongatum of the South Africa and South America. Whether the variance occurred among the above areas belongs to the intraspecific or interspecific variation, more morphometric data of the juveniles, males and the sequences of rDNA were needed, so we could be more acknowledged about the variability of this cosmopolitan species.

並列關鍵字

Variablity ； Xiphinema elongatum ； ribosomal DNA ； rDNA ； internal transcribed spacer ； ITS-1 ； ITS-2