Pathogenicity and histopathology of Pratylenchus thornei populations on selected chickpea genotypes

Abstract

Four populations of Pratylenchus thornei from different locations were tested for reproductive fitness in axenic carrot disc cultures and for pathogenicity to chickpea cultivars JG 62 and UC 27 and lines K 850 and ILC 1929. Parasitism and histopathology on selected chickpea genotypes (JG 62, UC 27 and lines ILC 482, ICC 11324 and ICC 12237) were also investigated. Reproductive fitness, assessed as the ratio of the final number of nematodes per carrot disc to the number of nematodes inoculated, was similar among the populations tested and the four populations reproduced to a similar extent in a given chickpea genotype. However, the extent of reproduction was significantly affected by the chickpea genotype, JG 62 and UC 27 being the best and poorest hosts, respectively. Pathogenicity to chickpea genotypes was assessed by the difference in fresh root and dry shoot weights between infected and uninfected plants 90 days after inoculation. Plant growth was significantly reduced by the four nematode populations in all chickpea genotypes, with the exception of cv. JG 62, which was tolerant of P. thornei. Severity of root necrosis caused by nematode infection was similar for all populations. Histopathological studies of chickpea genotypes infected by P. thornei showed that all were suitable hosts according to nematode reproduction and host reaction. P. thornei always migrated through epidermal and cortical cells by breaking down cell walls along the nematode pathway. In the most susceptible lines (ILC 482 and JG 62), damage to endodermal cells adjacent to nematode feeding sites was occasionally observed.

Morphological and molecular charaterisation of Pratylenchus parazeae n. sp. (Nematoda: Pratylenchidae) parasitizing sugarcane in China

“…Then, the necrotic root segments were sliced and the paraffin was removed following the description of Bachand and Castello (2001). Sections were stained with safranin and fast green (Sigma, USA) (Castillo et al 1998), mounted in pure glycerol, examined under the Nikon ECLIPSE Ni microscope and photographed.…”

Hybridisation of Australian chickpea cultivars with wild Cicer spp. increases resistance to root-lesion nematodes (Pratylenchus thornei and P. neglectus)

“…thornei has been found widely distributed in chickpea fields in Syria (Greco et al 1984) and in southern Spain (Castillo and Gomez-Barcina 1996), and reported to damage chickpea crops in various countries around the Mediterranean Sea and in India (Greco 1987;Sikora and Greco 1990). P. thornei has been clearly shown to produce severe lesions on chickpea roots and the histopathology has been well described (Castillo et al 1998). Di Vito et al (1992) demonstrated up to 58% loss in plant biomass and grain yield of chickpea cv.…”

Host suitability of 16 chrysanthemum cultivars and 22 crop species for Pratylenchus kumamotoensis

“…The nematode reproductive rates on 15 cultivars (Pf/Pi = 281-812) were comparable to the highest reproductive rates ever observed for Pratylenchus spp. in similar experiments (e.g., Rashid and Khan, 1975;Acosta and Malek, 1979;Castillo et al, 1998). The reproductive rate on 'Chrysanthemum Tsukuba No.…”