First Report of Ascochyta rabiei on Berseem Clover Seeds. F. Montorsi, Istituto Sperimentale per la Patologia Vegetale, Via Bertero 22, 00156 Rome, Italy. G. Di Giambattista, and A. Porta-Puglia. Istituto Sperimentale per la Patologia Vegetale, Via Bertero 22, 00156 Rome, Italy. Plant Dis. 76:538. Accepted for publication 26 October 1991. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0538B.
In 1989, seed samples of berseem clover (Trifolium alexandrinum L.), provided by P. Martiniello, were tested on water-soaked blotters (100 seeds per sample) to assess either infected or infested seeds for mycoflora. Ascochyta rabiei (Pass.) Labrousse (2), the causal agent of Ascochyta blight of chickpea (Cicer arietinum L.), was isolated from two seeds of one sample from Foggia in southern Italy. Patho-genicity tests were carried out by spraying a conidial suspension (1.5 X 106 conidia per milliliter from a single hyphal-tip isolate) on potted plants of berseem clover (Italian land race, 30 days old) and chickpea (cv. Calia, 15 days old) until runoff. The inoculated and uninoculated plants of both species were covered with transparent polyethylene bags for the first 48 hr after inoculation to increase RH and kept in a greenhouse (20 ± 3 C). Symptoms appeared after 10-12 days. On chickpea, typical leaf and stem lesions were observed. On berseem clover, small, elongated flesh-colored spots with brown rims appeared on leaves. The fungus was reisolated from both hosts. Uninoculated control plants were symptomless. These findings agree with those of Kaiser (1) and confirm the role of hosts other than chickpea in the epidemiology of A. rabiei. On berseem clover, distribution and effect of A. rabiei in the field, its localization in the seed, and its means of dispersal should be investigated further.