Morphological variability and pathogenic reactions of ...

Morphological variability and pathogenic reactions of F. oxysporum f.sp. ciceri isolates to cultivars of Chick pea

Morphological variability and pathogenic reactions of Fusarium oxysporum f.sp. ciceri isolates to cultivars of Chick pea Mohammad Ansar* and Mukesh Srivastava Department of Plant Pathology C.S.A. Univ. Agri. & Tech., Kanpur – 208 002, India *Department of Plant Pathology, Bihar Agricultural University, Sabour-813 210, Bhagalpur, India Date of Receipt: 27.05.2013; Accepted: 02.07.2013

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ABSTRACT All five isolates were found morphologically different and mycelial growth in different media was observed. Isolate Foc-5 preferred Czapek Dox medium for maximum growth (78.5 mm) while poor growth of Foc-4 (53.1 mm) in Asthan and Howkers medium. Isolate Foc-1 produced white dull colony whereas Foc-2 and Foc-4 rendered brown and pinkish white colony, respectively. Overall, biggest micro and macro conidia were found in isolates Foc-5 and Foc-3, respectively. Whereas, isolates Foc-2 and Foc-5 produced smallest micro and macro conidia, respectively. Most of isolates were more or less pathogenic to all tested chick pea cultivars. Awrodhi found resistant to most of the tested isolates, except Foc-5. Cultivar K-850 was found highly susceptible to isolates Foc-2 and Foc-5 and remaining three isolates rendered susceptible reaction. Key words: Cicer arietinum, Fusarium oxysporum, Morphological Variability.

Chick pea (Cicer arietinum L.) is the world’s third most important pulse crop, it is most important pulse crop in India, suffer from different diseases, Fusarium oxysporum f sp. ciceri is the most serious (Patil et al., 2005). The pathogen is both seed and soil borne; facultative saprophyte and can survive in soil up to six years in the absence of susceptible host. Considering the nature of damage and survival ability of the fungus, use of resistant varieties is the only economical and practical solution. Most of the resistant varieties have been found to be susceptible after some years because of breakdown in their resistance or a variety which exhibit resistance in one area may show susceptibility in another might be due to variability in pathogenic isolates. In the present study emphasis has been given on the morphological and pathogenic variability among the isolates. Materials and Methods Fusarium oxysporum f.sp. ciceri were sampled from 5 locations of central Uttar Pradesh.

viz. Kanpur Dehat, Fatehpur, Unnao, Auriya and Etawah. Isolates were named for Kanpur Dehat Foc-1; Fatehpur Foc2; Unnao Foc-3; Auriya, Foc4 and Etawah Foc-5. To find out the suitable medium and nutritional requirement, isolates of Foc., five culture media viz. Asthana and Hawker’s (AH), Czapek’s Dox (CzD), potato dextrose agar (PDA), Richard agar (RA) and corn meal (CM) media were tested by placing 5 mm dia. of mycelial disc of 6-day sporulating culture. Inoculated plates were incubated at 25±2ºC for five days. Observations on colony dia. and pigmentation were recorded. Parameters like width and length of conidia were studied concerning morphological character of different isolates. Minimum 50 microand macro-conidia were measured under compound microscope (40× magnification). A conidium considered germinated when the germtube length was equal or more than the width of the conidium. The field soil was autoclaved at 15 psi (120 ºC) for 15 min. for two successive days. Inner surface

Ann. Pl. Protec. Sci. 21 (2) : 345-348 (September, 2013)

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of the pots (30 cm dia) was disinfected with 0.25% mercuric chloride. Mass culture of isolates was prepared using autoclaved wheat grain. Flasks containing sterilized wheat grain (200 g) were inoculated with 4 mycelial discs of 5 mm dia. The inoculated flasks were exposed to incubation at 27ºC for 7 days. Manual shaking of the flasks were performed at 2 days interval after inoculation to get profuse and uniform growth of the mycelium. The content of flask was mixed with the soil (1:9) and earthen posts were filled with the inoculum-soil mixture; and kept for 3 days before sowing. Five cultivars of chick pea viz. K850, Radhey, Pusa 256, JG 315 and Awrodhi were used. Ten seeds of each cultivar were sown in the earthen pots containing soil mixture and watered when required. The reaction of cultivar was assessed as R (Resistant) 0.1-10%, MR(Moderately resistant) 11-20%, MS (Moderately susceptible) 21-40%, S (Susceptible) 41-60% and HS (Highly susceptible) 61-100%

Different media showed marked variation in radial mycelial growth. Interaction of different isolates and media also exhibited significance which indicated that every isolate had different ability to utilize the ingredients in the media. Foc-5 preferred CzD for maximum growth (78.53 mm) while poor growth by Foc-4 (53.08 mm) was observed in Asthan Howkers agar medium. Bardia and Rai (2008) reported that CzD medium supported the growth of F. cumini. Patil et al. (2005) also support the finding of the this study. Mycelium of Foc-1, white dull with average colony dia was 61.07 mm and average micro and macro conidia measuring 6.5 x 2.7 and 27.5x6.8 mm, respectively. Brownish mycelium of Foc-2 with average colony dia. 62.80 mm and micro conidia measuring 6.3 x 2.0 mm, macro conidia were absent. Colony dia. 67.26 mm was observed in Foc-3 mycelium was white fluffy, aerial lack of micro conidia size of macro conidia measure 27.3 x 7.9 mm. Cottony pinkish white mycelium was observed in Foc-4 with average colony dia 59.76 mm and average size of micro conidia was 5.4 x 2.5 mm. Dull white mycelium of Foc-5 (Patil et al., 2005) with average colony dia 69.18 and micro and macro conidia measuring about 7.5 x 2.9 and 27.0 x 5.8 mm respectively.

Results and Discussion Particular isolate had an ability to utilize the specific substrate for their growth and multiplication. Maximum growth had observed in Foc-5 (69.18 mm) followed by Foc-3 (67.26 mm) CzD and PDA medium supporting the maximum growth, respectively. Asthana & Hawker’s and Richards media was supported the minimum growth. Similar such study on morphological, cultural and pathogenic variability was reported on Foc on chick pea by Singh et al. (2011).

Among all five isolate of Foc, only three showed pigmentation. There were variations in isolation of Foc on the basis of cultural characters, colony dia. and size of macro and micro conidia. The present investigation confirmed this finding as

Table 1. Effect of media on radial growth of Fusarium oxysporum f. sp. cicerix. Radial growth (mm) Media Foc-1 Asthana & Hawker’s Czapeks Dox Potato Dextrose Agar Richard’s Corn Meal Agar Mean CD (P=0.05)

56.23 65.16 67.23 57.75 59.00 61.07 8.77

Foc-2 A B Bc Ab Abc

62.36 72.38 63.03 61.48 54.78 62.80 10.61

Foc-3 a b a a a

66.11 72.68 70.70 60.85 65.96 67.26 7.26

Foc-4 a b b a a

53.08 70.78 63.47 54.00 57.50 59.76 7.44

Foc-5 a b b a a

60.16 78.53 74.56 64.46 68.20 69.18 1.93

A B C D E

Values followed by a common letter in a column are not significantly different.

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Morphological variability and pathogenic reactions of F. oxysporum f.sp. ciceri isolates to cultivars of Chick pea

Table 2. Morphological characteristics of used isolates of Fusarium oxysporum f. sp. ciceri. Measurements Isolate

Foc-1 Foc-2 Foc-3 Foc-4 Foc-5

Colony dia. (mm)

Microconidia ( m)

Macroconidia ( m)

Colony Characteristics

Pigment*

61.07 62.80 67.26 59.76 69.18

6.5 × 2.7 6.3 × 2.0 Absent 5.4 × 2.5 7.5 × 2.9

27.5 × 6.8 Absent 27.3 × 7.9 Absent 27.0 × 5.8

Dull white Brown White and fluffy Pinkish white Dull white

– + + + –

*Appearance of pigmentation, (-) absence and (+) presence of pigment.




Table 3. Evaluation of chick pea cultivar against different isolates of F. oxysporum f. sp. ciceri. Isolates Cultivar

Foc-1

K-850 Radhey Pusa 256 JG 15 Awrodhi Foc-2 K-850 Radhey Pusa 256 JG 15 Awrodhi Foc-3 K-850 Radhey Pusa 256 JG 15 Awrodhi Foc-4 K-850 Radhey Pusa 256 JG 15 Awrodhi Foc-5 K-850 Radhey Pusa 256 JG 15 Awrodhi CD Isolates (P=0.05) Cultivation Interaction

Disease Incidence (%) Expe -1 46.7 50.0 16.7 10.0 6.7 63.3 50.0 30.0 20.0 10.0 46.7 20.0 13.3 6.7 10.0 53.3 13.3 16.7 6.7 3.3 70.0 26.7 30.0 20.0 13.3 9.47 5.53 12.38

Expe -2 50.0 53.3 13.3 6.7 3.3 70.0 60.0 36.7 6.7 6.7 56.7 13.3 16.7 3.3 10.0 43.3 26.7 16.7 13.3 10.0 83.3 36.7 16.7 16.7 23.3 0.79 0.71 1.59

Average 48.3 51.7 15.0 8.3 5.0 66.7 55.0 33.3 13.3 8.3 51.7 16.7 15.0 5.0 10.0 48.3 20.0 16.7 10.0 6.7 76.7 31.7 23.3 18.3 18.3

five isolates produced different growth on nutritional media. These results also supported the observation of Bardia and Rai (2008). The reaction of five cultivars of chick pea to five isolates of Foc from different locations was assessed in pot culture study in a glass house. The cultivar reaction to the isolates showed wide range of pathogenicity (Singh et al., 2010). On the basis of disease incidence in different chick pea cultivars against pathogen grouped in various resistant categories. The isolates were more or less pathogenic to all tested varieties (Table 3). However, all isolates were found weakly pathogenic to cultivar Awrodhi (Table 4). Isolates Foc-2 and Foc-5 showed a reaction explaining moderately resistant to cultivar JG-2, while Foc-1, 3, and Foc4 were found resistant. A moderately resistant reaction was observed for cv. Pusa-256 against the isolates Foc-1, 3, and Foc-4, whereas Foc-2 and Foc-5 showed moderate susceptibility. Interaction Table: 4 Reaction of chick pea cultivar to isolates of Fusarium oxysporum f. sp. ciceri (Pot test). Reaction to differentials Isolates

K- Radhey Pusa 850 256

JG Awrodhi 15

Foc-1 Foc-2 Foc-3 Foc-4 Foc-5

S HS S S HS

R MR R R MR


S S MR MR MS

MR MS MR MR MS

R R R R MR

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Mohammad Ansar and Mukesh Srivastava




between Radhey with isolates Foc-1 and Foc-2 were susceptible but isolates Foc-3 and Foc-4 were moderately resistant, however, Foc-5 found moderately susceptible. Every isolates found highly aggressive to cv. K-850; Foc-1, 3 and Foc-4 exhibited susceptible reaction while isolates Foc-2 and Foc-5 found highly susceptible reaction. It indicated the variation and ability to cause wilt in chick pea determined by the degree of aggressiveness among the isolates. The present study also supporting the findings of Minnatullah and Kumar (2005) while working on chick pea variability. Singh et al. (2011) worked on reaction of genotypes of chick pea, 45.5% plant mortality and G1 was least virulent showing only 20.1% plant mortality.

Minnatullah, Md. and K. Kumar (2005). Pathogenic variability to Colletotrichum falcatum. Ann Pl. Protec. Sci. 13: 500-501 Patil, P.D., S.S. Mehetre, V.K. Mandare and G.N. Dake (2005). Pathogenic variation among Fusarium isolate associated with wilt of chick pea. Ann. Pl. Protec. Sci. 13: 168-171. Singh, S.K., Bikram Singh, V.B. Singh and Reena (2011). Morphological, cultural and pathogenic variability among the isolates of Fusarium oxysporum f. sp.ciceri causing wilt of chick pea. Ann. Pl. Protec. Sci. 19: 155-158. Singh, V.K., Prem Naresh, S.K. Biswas and G.P. Singh (2010). Detection, location and survibility of Fusarium oxysporum f. sp. lentis in seeds of lentil. Ann. Pl. Protec. Sci. 18: 529-532.

References Bardia, P.K. and P.K. Rai (2008). Variability in Fusarium oxysporum f. sp.cumini causing cumin wilt. Ann Pl. Protec.Sci. 16: 444-448.

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