SURVEILLANCE, CHARACTERIZATION AND MANAGEMENT OF LENTIL ANTHRACNOSE PATHOGEN

Abstract

Anthracnose of lentil incited by Colletotrichum lentis Damm. is one of the most significant fungal threats to lentil (Lens culinaris Medikus) cultivation worldwide. A lot of data concerning disease has been published worldwide; however, no detailed information prior to this work was available in our country Pakistan. The present research encompassing the anthracnose disease incidence (DI) and disease severity (DS) in the major lentil growing districts of the Punjab province. The correct documentation of pathogen along with morphological characterization of isolates and status of available lentil accession was done. To begin with; a two-year anthracnose survey (2014 and 2015 crop season) was completed in 13 lentil growing districts of Punjab, comprising of; Rawalpindi, Chakwal, Attock, Jhelum, Gujrat, Sialkot, Narowal, Mianwali, Khushab, Jhang, Bhakkar, Layyah and Muzaffargarh. Consequently, 162 disease samples were collected from private/ farms/ government research institutes. These samples yielded 102 C. lentis isolates. Survey revealed disease prevalence in 100% areas/ districts. The highest DI 68% and DS 7 were found in district Khushab, whereas the lowest DI 21% and DS 3 were recorded in district Jhang. Morphological characterization of 102 C. lentis isolates showed flat growth habit in 65% isolates together with a variety of culture colours i.e. black-salmon, iron-grey, orangewhitish, and pale salmon on oat meal agar. Number of days required to fill 90 mm petri plates varied from eight to ten days, whereas, the maximum isolates 63% took nine days (mean growth 10 mm/day). Majority of conidia (57%) were slightly falcate in shape, conidia were hyaline, smooth walled, aseptate ranging from 15.8- xxiii 20.02 × 2.86-4.25 μm. Isolates exhibited almost equal percentage of two shapes of appressoria i.e. rounded to ellipsoidal (51%) and clavate (49%) ranging from 7.08- 11.04 × 4.03-7.05 μm, brown in colour, smooth, solitary or occurring in loose clusters. Study revealed translucent to yellowish brown setae measuring 40.7-85 × 4.8-6.4 μm. Pathogenic variability employing 51% of C. lentis isolates using accessions; NIAB Masoor-2006, Punjab Markaz-2009, Punjab Masoor and NIAB Masoor-2002 taken as differential lines manifested majority of isolates virulent, accordingly accessions were found susceptible to maximum number of isolates. Individually, isolate CLK-63 (recovered from samples of district Khushab) was found the most virulent rendering all accessions highly susceptible to anthracnose. Molecular confirmation of isolate CLK-63 proved it to be true C. lentis. Management of anthracnose based on host plant resistance, of 31 lentil accessions at seedling and flowering stage against isolate CLK-63 indicated Masoor-89, Masoor-86, Masoor-89 bold seeded, Masoor-2004, NARC- 11-1, 08505, Punjab Massor-2009 and Shiraz-96 as resistant accessions to anthracnose.