エンドファイト特性を利用したライグラス類への環境抵抗性の付与

Neotyphodium内生菌产生动物毒性，另一方面，提供期望的性状，包括抗虫性和抗旱性。为了将内生菌的特性应用于牧草育种，开始，于1990年对德国阿尔卑斯山和北上高原的多年生黑麦草进行了内生菌感染率调查。两种生态型均未发现内生菌。通过对多年生黑麦草和高羊茅市售种子的内生真菌感染率进行调查，结果表明：多年生黑麦草和高羊茅种子的内生真菌感染率均高于高羊茅种子。通过这两个物种，品种之间的差异很大。草坪型品种内生真菌感染率高于牧草型品种。不同原产国的品种比较，美国品种的感染率最高，其次是欧洲品种，日本品种最低。 ...更多信息 日本原产的大豆品种均无内生真菌感染，感染率均为0.0%。在选择过程中必须排除具有内生菌的个体植物。内生真菌的植物在潮湿的气候条件下的适应性较差，如在日本。在盛冈等地引起动物疾病的黑麦草秸秆和牛毛草秸秆中这些生物碱的浓度较高。岩手县销售的一些高羊茅秸秆表明麦角缬氨酸浓度高于动物疾病的阈值水平。在日本，在阈值水平以下发生了一些动物疾病。这可能意味着日本的阈值水平低于美国。日本的气候条件下，内生菌感染的植物适应性低。然后，在实际条件下调查感染率。在这些情况下，如高尔夫球场，草种被过度播种在草坪上，草坪的地面覆盖度差，内生菌感染率低。而在运动场裸地上播种时，高羊茅的内生菌率为0，而多年生黑麦草的内生菌率较高，因此，利用含有内生菌的遗传改良草坪草具有重要的价值。利用内生真菌的特性进行饲料作物育种，需要更多的知识，包括植物和内生真菌之间的生长速度差异。少

Neotyphodium endophyte produces animal toxicoses, and on the other hand, gives desirable traits including resistance to insects and to drought. This study was to utilize the characteristics of endophyte into grass breeding.To begin with, endophyte infection rate was investigated for perennial ryegrass ecotypes collected from highlands in German Alps and Kitakami highland by 1990. Any endophyte was not observed in both ecotypes. This indicates that endophyte does not contribute to cold resistance.Endophyte infection rate was investigated for marketed forage seed of perennial ryegrass and tall fescue. Through these two species, there was great difference among cultivars. Compared cultivars between their use, endophyte infection rates were higher in turf type than in forage type. Compared cultivars among countries originated, US cultivars indicated highest infection rate, followed by European cultivars, and Japanese cultivars were lowest.Five perennial ryegrass cultivars and three tall fe … More scue cultivars originated in Japan were all free from endophyte, and the infection rates were all 0.0%. Individual plants with endophyte must be excluded from in the process of selection. Plants with endophyte may be less adaptable under wet weather condition like in Japan.Ryegrass straw and fescue straw caused animal disorder at Morioka and other places showed high concentration in these alkaloids. Some tall fescue straw marketed in Iwate prefecture indicated higher ergovaline concentration than threshold level of animal disorder. There are some cases that animal disorder occurred in Japan under the threshold level. This may mean that the threshold level in Japan is lower than that in USA.Endophyte infected plants are low adaptable under Japanese weather condition. Then, the infection rate was investigated under practical conditions. In these cases, as golf courses, grass seeds were over-seeded on turf where ground coverage by grasses was worse, endophyte infection rates were low. However, when grass seeds were seeded newly on bare ground in sports ground, the rate was high in perennial ryegrass although that was 0% in tall fescue.Use of genetically improved turf-grasses containing useful endophytes is of great value. To use endophyte characteristics for forage crop breeding, more knowledge including difference of growth rate between plants and endophyte fungi are needed. Less