Screening Wild Cucumis spp. in the Field and with Artificial Seed Inoculation against Fusarium oxysporum sp. Melonis

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Cucurbit Genetics Cooperative Report 13:18-19 (article 7) 1990

Pious Thomas and T. A. More
Division of Vegetable Crops, Indian Agricultural Research Institute, New Delhi 110012, India

Wilt disease caused by Fusarium spp. Is a serious problem of muskmelon (Cucumis melo L.) in the river beds of North India and other production areas (1,2,5). The Jamuna river bed showed a higher prevalence of F. solani compared to F. oxysporum, but isolates of the latter were more virulent (3). The performance of wild Cucumis spp. in field screening and with artificial inoculation (5 × 106 spores/ml) against F. oxysporum f. sp. melonis are furnished in Table 1. All the wild Cucumis spp. used in this study, except C. melo var. callosus (25% mortality) showed high resistance under field conditions. In the artificial inoculation study, C. dipsaceus, C. meeusii and C. anguria var. longipes failed to germinate in the inoculated and uninoculated tests and among the others, only C. melo var. callosus showed good germination. C. figarei, C. zeyheri 1 and 2 and C. anguria var. longipes, exhibited high resistance (no mortality), while C. melo var. callosus and the susceptible check M3 showed 41.7 and 90.0% mortality, respectively, at 5 weeks after inoculation. The slight mortality observed in C. myriocarpus 1 and 2 and C. anguria were not definitely due to Fusarium infection since mortality was confined to weak plants and was observed in check plants as well.

At the 5 weeks stage, a second inoculation was done by drenching the soil mixture to saturation with freshly prepared spore suspension (5 × 106 spores/ml). Watering was suspended for two days before and after the second inoculation. A fresh set of 3 week old seedlings of M3 was similarly drenched in spore suspension and used as susceptible check. No further mortality was observed (5 weeks after second inoculation) in any of the wild species.

Identification of resistance in wild species opens the possibility of their utilization in breeding program. This opens the prospect for developing multiple disease resistant lines, incorporating CGMMV resistance (4) and Fusarium resistance of C. figarei. This project is underway.

Table 1. Performance of wild Cucumis spp. in field and with seed inoculation against F. oxysporum f. sp. melonis.

FIELD

SEED INOCULATION

Species
No. of Hills
% Mortality
No. of Plants
% Mortality
5 weeks
*10 weeks
C. myriocarpus 1

(GBNRa-1676)

 9 0 9 12.5 12.5
C. myriocarpus 2

(GBNR-1051)

 7 0 5 20.0 20.0
C. figarei

(GBNR-1084)

 6 0 26 0 0
C. meeusii

(GBNR-1800)

 6 0 – – –
C. dipsaceus

(GBNR-1774)

 7 0 – – –
C. zeyheri 1

(73252 H 9)

 6 0 2 0 0
C. zeyheri 2

(GBNR-1053)

(Tetraploid)

 6 0 13 0 0
C. anguria

(GBNR-1970)

 6 0 6 16.7 16.7
C. anguria var. longipes

(GBNR-1735)

 6 0 – – –
C. melo var. callosus

(Acc. No. 566)b

 8 25.0 24 41.7 41.7
C. melo M 3 – – 12 90.0 –
* – 5 weeks after a second inoculation
a – Source: Wageningen, The Netherlands
b – Source: Tamil Nadu, India

Literature Cited

  1. Bhaskaran, R. and N. N. Prasad. 1971. Certain biochemical changes in two Cucumis spp. in response to Fusarium infection. Phytopath. Mediterr. 10:238-243.
  2. Palodhi, P. R. and B. Sen. 1981. Fusarium wilt endangers river bed cultivation of cucurbits. Indian J. Mycol. Res. 19:51-56.
  3. Radhakrishnan, P. and B. Sen. 1981. Prevalence of Fusarium oxysporum and Fusarium solani (Mart.) Sacc. causing muskmelon wilt. Veg. Sci. 8:64-68.
  4. Rajamony, L., T. A. More, V. S. Seshadri and A. Varma. 1987. Resistance to cucumber green mottle mosaic virus (CGMMV) in muskmelon. Cucurbit Genetics Cooperative 10:58-59.
  5. Sen, B. and P. R. Palodhi. 1979. A disease of muskmelon caused by Fusarium solani (Mart.) Sacc. Curr. Sci. 48:166-167.