Survey on Soybean Parasitic Nematodes

대두증산을 위한 기생선충 조사

Survey on soybean parasitic nematodes has been undertaken in order to get an ideas about the distribution of nemic fauna. Total 71 soil samples were collected from soybean fields in Gyeongbug and Chungbug provinces. Eighteen species belonging to fourteen different genera were found associated with soybean, Glycine max. The results were as follows: Aphelenchus avenae, Circonemoides informis, Ditylenchus dipsaci, Helicotylenchus pseudorobustus, Heterodera glycines, Hirschmanniella imamuri, Meloidogyne hapla, Meloidogyne incognita, Paratylenchus pandus, Pratylenchus thornei, Pratylenchus vulnus, Psilenchus hilarulus, Rotylenchus sp. Tylenchorhynchus clay toni, Tylenchorhynchus dubius, Tylenchorhynchus nudus, Tylenchus sp. Xiphinema americanum were found in soybean fields. In frequency of occurring nematodes by localities, soybean cyst nematode was higher in Chungbug by $70\%$, while $50\%$ in Gyeongbug. But rook-knot nematode was higher in Gyeongbug by $54.1\%$, while $19.1\%$ in Chungbug. In density of nematode, Heterodera was the most dominant as 200.4 populations per 100ml soil, Meloidogyne as 107.1 populations, Rotylenchus, Xiphinema, Aphelenchus in decreasing order. In survey of loss, density of soybean cyst nematode in heavily infested fields was 155 cysts per 100ml soil while 35 cysts in slightly infested fields. Seventy percent of soybean yields was decreased when comparing with average 64.2kg/10a in heavily infested fields and average 209.5kg/10a in slightly infested. Correlation coefficients among number of soybean cyst and yields, pod weight, number of pod was negative as r- 0.57, 0.47, 0.38 over all localities.

대두에 기생하는 선충을 조사하기 위하여 경북 및 충북의 15개시군 총 71개포장에서 재료를 채집하여 선충을 분리 동정한 결과, Aphelenchus avenue, Criconemoides informis, Ditylenchus dipsaci Helicotylenchus pseudorbustus, Heterodera glycines, Hischmanniella imamuri, Meloidogyne hapla, Meloidogyne incognita, Paratylenchus panadus, Pratylenchus thornei, Pratylenchus vulmus, Psilenchus hilarulus, Rotylenchus sp. Tylenchus sp., Tylenchorhynchus claytoni, Tylenchorynchus, Tylenchorhynchus, Xiphinema americanm 등 총 8과 14속 18종이 검출되었으며, 그중에 Heterodera glycines가 가장 중요한 종으로 나타났다. 지역별 선충의 검출율에 있어서 콩 Cyst선충은 충북이 $70\%$, 지이 $50\%$로 충북이 높았고 반면에 뿌리혹선충은 경북 $54.1\%$, 충북이 $19.1\%$로 경북이 높게 나타났다. 전체포장에 있어서 Cyst선충의 절대밀도는 토양 100l당 200.4이며 상대밀도는 $40.2\%$로 가장높게 나타났고, 뿌리혹 선충은 절대밀도가 107.1이며 상대밀도는 $21.4\%$로 다음이였으며, Rotylenchus, Tylenchorhynchus, Tylenchus, Pratylenchus, Xiphinema, Aphelenchus등의 순이였다. 피해가 심한 포장에는 콩 Cyst의 밀도가 토양 100ml 당 평균 155개이고 경한 포장에서는 평균 35개로 밀도가 높았으며 수확량은 평균 64.2kg/10a로 209.5kg/10a에 비하여 $70\%$가 감소되었다. 전피해조사포장에 있어서 콩 Cyst선충수는 수확량, 협중, 협수간에는 $r=-0.75^{**},\;r=-0.47^{**},\;r=0.38^*$로 부의 상관관계가 있었다.