FREE AMINO ACID CHANGES DURING GERMINATION OF TELIOSPORES OF THE WHEAT BUNT FUNGUS,TILLETIA CARIES

Teliospores were aerated and agitated in a mineral salts medium and their free amino acid contents were analyzed at eight different times, from shortly after imbibition of water until just before germ tube emergence. In addition to the common amino acids, eight unidentified ninhydrin-positive components were detected. About 50 % or more of nearly each of the amino acids diffused out of the spores during the initial phase of germination. These released amino acids were actively taken up by the spores during the latter stages of germination. The free amino acids in largest amounts in the dormant spores of T. caries were arginine 15.0, glutamic acid 6.3, and alanine 3.7 μmoles per g dry spores. Together these three amino acids accounted for about 71 % of the total free amino acids in dormant spores of T. caries and T. controversa. The total amounts of free amino acids in spores of common bunt were much higher than in spores of dwarf bunt.     

LOOSE SMUT (USTILAGO TRITICI (PERS.) ROSTR.) OF WHEAT: PHYSIOLOGIC SPECIALIZATION AND REACTION OF VARIETIES IN ENGLAND

Three physiologic races of loose smut (named Ci, C2 and C3), found in wheat varieties grown at Cambridge, differ from those identified in Holland. The resistance or susceptibility of fifty-seven wheat varieties to races Ci, C2 and C3 has been determined. Experiments have shown that infection of an ear can take place over a period of several days. There is a close relationship between the percentage of plants attacked and the severity of attack in a single plant.     

小麦品种的耐肥性与光合作用

本试验以耐肥性不同的三个冬小麦品种为试材,研究了品种的耐肥性与光合作用的关系。结果表明,旗叶的光合速率顺序为;泰山一号(中度耐肥)>济南13(高度耐肥)>昌乐5号(不耐肥)。光合速率的绝对值虽因不同年度间环境条件的不同而有所变动,但品种间的差别则保持相对稳定。增施氮肥,能使昌乐5号的光合速率明显降低,而泰山一号和济南13的光合速率则因增施氮肥受到显著的促进。     

SLUG FEEDING BEHAVIOUR IN RELATION TO CONTROL WITH MOLLUSCICIDAL BAITS

The feeding behaviour of Deroceras reticulatam (Müller)presented with molluscicidal baits in laboratory and terrariatrials is described and discussed in relation to pest slug control.Both metaldehyde and Methiocarb appears to be more effectivein wet conditions and less repellent to slugs allowing moreactive ingredient to be consumed before termination of feeding (Received 16 November 1987; accepted 15 February 1988)