Effect of Methyl Jasmonate on Phytoalexins Biosynthesis and Induced Disease Resistance to Fusarium oxysporum f. sp. Vasinfectum in Cotton (Gossypium hirsutum L.)

Table 3

Effect of methyl jasmonate treatment on Fusarium wilt severity of cotton plant.

Incubation time (day)	Disease severity (score 0–6)
	MeJA/infected plants	No-MeJA/infected plants	No-MeJA/no-infected plants
0	0^a	0^a	0^a
2	1^b	1^b	0^a
4	1^b	2^c	0^a
6	1^b	2^c	0^a
8	2^c	3^d	0^a
10	1^b	3^d	0^a
12	1^b	3^d	0^a
14	0^a	3^d	0^a
16	0^a	5^e	0^a
18	0^a	6^f	0^a
20	0^a	6^f	0^a
22	0^a	6^f	0^a
24	0^a	6^f	0^a
26	0^a	6^f	0^a
28	0^a	6^f	0^a
30	0^a	6^f	0^a
32	0^a	6^f	0^a
34	0^a	6^f	0^a
36	0^a	6^f	0^a
38	0^a	6^f	0^a

FOV: Fusarium oxysporum f. sp. vasinfectum; leaves were treated with MeJA 5.0 mM, inoculated at 72 h (day 0) with FOV, and incubated at 25°C for 38 days. Disease severity (mean wilt score) was evaluated every two days using the following arbitrary scale: 0, no wilt attached or detached leaves; 1, 1–15% wilt attached or detached leaves (WADL); 2, 15–25% WADL; 3, 25–35% WADL; 4, 35–45% WADL; 5, 45–55% WADL; 6, 55–100% WADL. Disease severity was assessed on each plant, and the mean wilt score for each replicate was calculated. data are expressed as mean of three replicates; within row and column, numbers followed by a different letter are significantly different according to Duncan’s multiple range test at P = 0.05 level; MeJA: methyl jasmonate.