An Emerging Disease of Chickpea, Basal Stem Rot Caused by Diaporthe aspalathi in China

Chickpea (Cicer arietinum L.) is an important legume crop worldwide. An emerging disease, basal stem rot with obvious wilt symptoms, was observed in the upper part of chickpea plants during the disease survey in Qiubei County of Yunnan Province. Three fungal isolates (ZD36-1, ZD36-2, and ZD36-3) were obtained from the diseased tissue of chickpea plants collected from the field. Those isolates were morphologically found to be similar to Diaporthe aspalathi. Molecular sequence analyses of multiple gene regions (ITS, tef1, tub2, cal, and his3) indicated that the three isolates showed a high identity with D. aspalathi. Pathogenicity and host range tests of the isolates were performed on the original host chickpea and eight other legume crops. The isolates were strongly pathogenic to chickpea and appeared highly pathogenic to soybean, cowpea, and mung bean; moderated or mild pathogenic to adzuki bean and common bean; however, the isolates did not cause symptoms on grass pea (Lathyrus sativus). Diaporthe aspalathi was previously reported as a main pathogen causing the southern stem canker in soybean. To our knowledge, this is the first report of D. aspalathi inducing basal stem rot on chickpea worldwide.