Wood Decay Fungi Associated with Tamarind tree in Gujarat, India

. Fungi may cause internal decay, cankers, loosening of tissue and cell walls result into weak forks in the trunk and large branches. Tree rot may be associated with root decay, damage to foliage and fruits. Wood decay fungi isolated from Tamarindus indica were Daldinia concentrica , Schizophyllum commune , Flavodon flavus, Irpex hydnoides , and Phellinus fastuosus, in which D. concentrica causing canker rot is reported for the first time from India and F. flavus and I. hydnoides P. fastuosus are recorded for the first time on T. indica wood causing white rot. During canker rot, formation of bark canker and extensive internal decay of wood was observed; as a result the tree growing in the M.S. University campus became structurally unstable and broken off at the canker face. Early detection and removal of such hazardous branches of trees is advocated to avoid loss of life and property.


INTRODUCTION
Wood deteriorating Fungi cause three different types of wood decay. They are white rot, brown rot and soft rot. In brown rot -cellulose and hemicellulose are broken down in the wood substrate while lignin remains preserved in slightly modified form (Green and Highley 1997). It is caused by family Polyporaceae usually in conifers (Schwaze et al., 2000). The term white rot has been used to describe forms of wood decay in which the wood assumes bleached appearance and where lignin is also broken down with cellulose. Members causing white rot include members of Basidiomycetes and Ascomycetes particularly Xylariaceae (Sutherland and Crawford 1981). Third type of decay is termed as soft rot, members of Deuteromycetes and Ascomycetes cause it. Fungus produces cavities in secondary wall; these are oriented longitudinally to the cell axis. Soft rot is usually superficial and generally occurs in the wooden pieces with high moisture.
Tamarindus indica L. is an economically important multi-use tree, found in several countries of Asia, Africa and South America. It is a source of timber, fruit, seeds, fodder, medicinal extracts and potential industrial components. The heartwood is dark in colour and is very hard, durable and resistant. The sapwood is yellow in colour and is far less durable than the heartwood. Wood deteriorating fungi belonging to Aphyllophorales in which polypores and corticioid fungi included are immensely important in natural ecosystem as decomposers of wood, recycling the nutrients and minerals in the wood and releasing them over a long period of time (Natarajan and Kolandavelu 1998). Many species are associated act as mild to severe pathogens of living forest trees (Natarajan and Kolandavelu 1998). The wood decay by Polyporus luteo-umbrinus Romell on root and dead fallen branches of Heritiera minor was reported from Baroda (Bakshi, 1971). Arya (2004) reported wood decay fungi like Ganoderma lucidum (Fr.) Ryv., Phellinus nilgheriensis (Mont.) Cunn., Trametes cingulata Fr., and T. varians van der Bij. from Baroda and Shoolpaneshwar wildlife sanctuary. Arya et al (2008) reported Lenzites sterioides for the first time on T. grandis. Randhawa et al. (2000) reported Cryptococcus neoformans and other yeast like fungi from decaying tree trunk of Butea monosperma and T. indica. Some fungi already reported on tamarind tree, there part and authority was given in Table 2.

MATERIALS AND METHODS
During 2006 -2014 a study was undertaken near D.N. Hall ground of the Maharaja Sayajirao University of Baroda to find out the association of wood decay fungi on five T. indica trees and also how the breaking of branches from the main stem took place ?. The breaking pattern, cavities, decay and fungal growth were recorded. The morphological characters like colour, texture, shape, size and the host trees were noted in the field. All the specimens like the fungi, decomposed wood, etc. were collected in clean polythene bags and brought to the laboratory for examination and isolation of fungi. They were kept in the brown paper packets provided with the naphthalene balla to avoide insect attack. For microscopic studies thin sections of dried materials were mounted in 2% KOH solution. For staining the hyphae thin sections were placed in cotton blue mixed with lactophenol. For amyloidy test melzer's reagent was used. All the mesurements were taken three time and the average values were given. All the collections have been deposited in the department of botany museum, M.S. University of baroda, Vadodara (Bakshi 1971, Ryvarden 1991. Isolations were made on malt extract agar medium and they were identified.

RESULTS AND DISCUSSION
Wood decay fungi associated with T. indica belonged Basidiomycotina, Ascomycotina, and Deuteromycotina. The isolated fungi can be classified into families like Xylariaceae, Schizophyllaceae, Polyporaceae and Hymenochaetaceae. Wood decay fungi associate with tamarind tree were 4 Ascomycotina members in which Aspergilus niger causing sap rot, Chaetomium globosum and Xylaria polymorpha causing soft rot and Daldinia concentric causes canker rot. Basidiomycotina members were 4 in which Flavodon flavus, Phellinus fastuosus, Irpex hydnoides Schizophyllum commune caused white rot on stem. Deuteromycotina members were 6 in which Alternaria alternata Phomopsis tamarindii, Pestalotiopsis sp. causes leaf spot in leaves, Botryospaeria ribis, Curvularia prasadii and Lasiodiplodia theobromae causes soft rot in dead and living stem (Table 1). Based on the morphological and anatomical characters, the detailed descriptions of the five wood degrading fungal species were given below.

Plate II
The ascocarps of Daldinia concentrica (Bolton) Cesati and de Notaris were ball-shaped, with a hard, shiny black fruiting bodies up to 6 cm in size (Plate I. Fig. A). It resembles a chunk of coal, which gives it several of its common names, including coal fungus and carbon balls. The flesh of the fungus was brown and silvery-black inside, and is arranged in concentric layers (Plate I Fig.  B). Each layer represents a season of reproduction. The asci are cylindrical and arranged inside the flask-shaped perithecium. When each ascus becomes engorged with fluid it extends outside the perithecium and releases spores. Perithecium shows attachment of asci with 8 inequilaterally ascospores (Plate I. Fig. C). The basidiocarp of Schizophyllum commune Fr. was shell-shaped, without stipe, narrow, laterally attached to substrate, 1 -4 cm broad; gray-white; surface densely covered with hairs (Plate I. Fig D), radialy wrinkled, grooved; margin acute, incurved, with thick hairs. Lamellae radilly divergent from point of attachment, gray, when dry edges split into two, moistened convergent; distant. Flesh thin, white, tough, elastic; Dry specimens after rain revive. Spores cylindric, smooth, colourless, 6.3 x 2.5 µm in size.
Basidiocarps of Phellinus fastuosus (Lev.) Ryv. was perennial, imbricate, sessile, broadly attached applanate, up to 16 x 25 x 6 cm thick; upper surface rusty brown, matted, tomentose in narrow concentric zones, up to 1mm thick black crust; margin usually thick and obtuse, velutinate, golden yellow, sterile underneath; pore surface golden yellow reddidh brown in older specimens, tubes concolorous, distinctly stratified, 2-4 mm thick in each layer; pores round, 8-10 per mm; context golden brown up to 3 cm thick, limited on upper surface with black thin line. Hyphal system dimitic; hyphal seate absent; basidia clavate 6-12 x 6.35 µm thick, spores broadly ellipsoidal, rusty brown, 6.3 x 4.5 µm, thin-walled. The fungus was earlier reported on Shorea rubusta and causes decay in the heartwood at butt region (Bakshi 1971) Tamarind heartwood was considered to be a very durable timber and was used in furniture making as it takes on a good polish (Jayaweera, 1981). The wood is hard, heavy and dark brown. It was highly wind-resistant, with strong, supple branches, gracefully drooping at the ends, and has dark-gray, rough, fissured bark (Jayaweera, 1981). Different types of rots causing damage to tamarind wood were saprot by Xylaria euglossa, brownish sap rot by Polyporus calcuttensis, white rot by Trametes floccose, Stem rot by Pholiota gollani, Stem canker by Hypoxlon nectriodes, Trunk and Root rot by Stereum nitidulum and root and wood rot by Ganoderma lucidum (Bakshi 1971 andNatarajan andKolandavelu 1998).
Many fruiting bodies of D. concetrica were found associated with decaying tree and causing canker rot was recorded for the first time from India (Bilgrami et al. 1979, 1981, Jamaluddin et al. 2004and Bakshi 1971. More fruiting bodies of S. commune and less fruiting bodies F. flavus I. hydnoides were found associated with it and were causing white rot. It is evident from Plate II Fig.  A,B,C that tamarind tree was broken during high velocity winds where the wood was degraded by wood decay fungi. The tamarind tree was observed broken two-side branch at forking in August 2007 (Plate II. Fig. A.) and one more side branch in July 2008 due to 50kmph velocity of wind. The branch attached to trunk become weak due to decay of heart wood where it creates cavity (Plate II Fig B). Heart wood rotting area shows the mycelial patches and with cubical breaking of degraded wood on drying (Plate II Fig. C). Infected heart wood of plant secreted a gummy substance which changed colour of heart wood from brown to black (Plate II Fig. D). Present study report occurrence of F. flavus, I. hydnoides and Phellinus fastuosus were recorded for the first time on T. indica. It is known that many wood decay fungi penetrate into the stem via injuries in which heart wood or ripe wood has been exposed. The probability of infection increases with increasing size of the wound. In addition, fungi have numerous other strategies to evade the protective bark of the tree and penetrate into the interior of the stem. (Rayner and Boddy, 1988). The majority of wood decay fungi which impair the stability and fracture-safety of trees belong to the heat-rot pathogens (Schwarze and Engels, 1997). In the present paper also the wood decaying fungi like F. flavus, I. hydnoides and P. fastuosus causes white rot which leads to the lose of stability and resistance to wind blow of tamarind tree. The white rot pathogens S. commune causes selective utilization of lignin (Blanchette et al., 1988). Basidiocarps of S. commune were seen on tamarind branches which may degrade the lignin also resulting in the lose of stability and resistant to wind blow. The physiology of wood degrading fungi has been studied. It was found that when basidiomycetes produce sporophores, endocellulae production can increase up to 10 fold (Wood and Leatham, 1983) and stored nutrients are transported to the wood surface for sporophore production (Gruen and Wu, 1972) and this makes wood weak and brittle. Fomes fomentarius (P. fomentarius) caused 21% weight lose in beech and 23% in oak tree (Schwarze et al. 2000). In the present paper the white rot fungi formed sporophores on the tamarind trees causing the stems weak and brittle. Reiess (1986) reported that various fungal spores present in air germinate and colonize sap wood. These fungi were present on injured area of tree. This is because availability of food in injured part. Mold causes structural changes in wood and do not impair mechanical properties. In the present paper also the sap rot and soft rot fungi were isolated from the tamarind dead stem which is using the sap wood (Table 1).

CONCLUSIONS
The tree breakage in the present study was found to be associated with canker rot and white rot. The infected tree became structurally unstable and broke off at the canker face. Canker rots and white rot are known to cause trunk breakage due to extensive internal decay in the tree (Tattar 1989). T. indica tree is highly wind resistant but the branches were broken at forking due to canker rot caused by D. concentrica and white rot fungi i.e. S. commune, F. flavus I. hydnoides and P. fastuosus cause white rot which weakens the living stem. Breakage of tree during high velocity winds and storms causes damage to life and property is prevalent in man made forests and urban plantations. Such damage due to hazardous trees can be prevented if early detection through symptoms of canker rot and signs of fruit bodies are made. Such cases need to be investigated in detail in order to avoid their recurrence in cities.