Original Research Article……….. International Journal of Agricultural Invention (online available at www.agriinventionjournal.com)

International Journal of Agricultural Invention 1(1): 65-70: June, 2016 ISSN: 2456 – 1797 (P)

Studies on the histomorphology of leaf galls on scholaris L. () induced by Pauropsylla tuberculata Crawford

*Om Datta, S. C. Dhiman

Department of Zoology, M. S. College, Saharanpur, U.P., *Corresponding email: [email protected]

ARTICLE INFO ABSTRACT Original Research Article The present was undertaken the study investigate histomorphology of the leaf galls on Received on February 27, 2016 Accepted on March 29, 2016 Alstonia scholaris induced by Pauropsylla tuberculata. It was noted that Pauropsylla tuberculata forms pouch galls on the leaf of Alstonia scholaris. Galls develop due to the Article Authors Om Datta, S. C. Dhiman feeding of nymphs which induce metaplasia in the localized host tissue. In present Corresponding Author Email [email protected] investigation histomorphology of young, mature and old galls is given. Number of galls per

PUBLICATION INFO plantwas also studied and number of galls and infestation percentage were also calculated. International Journal of Agricultural Invention (IJAI) KEYWORDS RNI: UPENG/2016/70091 Galls, Alstonia Scholaris, Pauropsylla Tuberculata, Histology, Morphology, Number of ISSN: 2456-1797 (P) Galls Vol.: 1, Issue: 1, Pages: 65-70 Journal Homepage URL http://agriinventionjournal.com/ DOI: 10.46492/IJAI/2016.1.1.10 HOW TO CITE THIS ARTICLE Datta, O., Dhiman, S. C. (2016) Studies on the histomorphology of leaf galls on Alstonia scholaris L. (Apocynaceae) induced by Pauropsylla tuberculata Crawford, International Journal of Agricultural Invention, 1(1): 65-70. DOI: 10.46492/IJAI/2016.1.1.10

Alstonia scholaris L. is a beautiful foliage tree MATERIALS AND METHODS with large canopy and because of this it has become a popular ornamental tree in land scapes and gardens in Gall infected leaves were collected and warm and temperate regions of the world. It is brought to laboratory for studying morphological preferred as road side in cities, as it is highly changes in infested leaves in comparison to healthy affected to pollutants. However, gall caused by leaves. External feature, internal structure, variation Pauropsylla tuberculata (Homoptera – Psylidae) on in shape and size of different stages of galls, i.e., the leaves, young stems and even on of newly formed gall, young, mature and old galls, were this highly prized tree, adversely affect the looks and studied under binocular microscope. For economic value. According Mani (1973), the gall is histochemical analysis, samples of leaves with galls, the product of the interspecific association between a successive stages of development were fixed in FAA plant and an organism characterized by plant reaction (formalin, acetic acid and 50% ethyl alcohol, 1:1:18, with some abnormal growth in some respect. Very, v/v), dehydrated with an ethanol series and embedded few studies have been made on different aspects of in paraffin (Johansan, 1940). T. S. and L. S. (12 galls of different species of insects. Gupta (2011) micron thick) were cut with a rotary microtome. investigated the different enzymes involved in phenol Hand cut sections using razor were also made. The metabolism of gall and normal tissue of insect cut sections were stained with safaran in and fast induced leaf galls of some plant in Rajasthan. green (Sass, 1951) and mounted in DPX. Srilakshman et al. (2012) carried morphological studies and physiochemical evaluation in Pongamia RESULTS AND DISCUSSION pinnae leaf galls. Dhiman and Kumar (2013) made studies on the impact of galls formation on Alstonia Pauropsylla tuberculata forms pouch galls scholaris induced by Pauropsylla tuberculata. In on the leaves of A. scholaris, are countless. P. present paper an effort has been made to investigate tuberculata lays eggs on the abaxial surface of the histomorphology of the leaf gall on Alstonia scholaris induced by Pauropsylla tuberculata.

International Journal of Agricultural Invention, 1(1): 65-70, June, 2016 65

Om Datta and S.C. Dhiman leaves. Eggs are laid singly or grouped at more The sclerenchyma cells are also encircled the than one place. Probably at the site of egg laying vascular tissue. or after hatching eggs, the nymphs feed on leaves provide stimulus which lead to the formation of Histology of galls galls. The fully developed galls typically contain several tissue types that are organized in layers. The outermost layer of plant epidermis and inside In about 48 hours after oviposition, as a the epidermis, a layer composed of thick walled result of embryo growth, the eggs incline itself in highly lignified cells which serve to protect young such a way that the operculum touches the plant instars. Inside the protective layer, a layer of surface, facilitating easy migration of nymph after nutritive cells lining the central chamber. These the dehiscence of the eggs. 1st nymphal instars cells provide a rich source of protein, sugars and feed on the mesophyll parenchyma cells which other nutrients needed for insect growth and development. become metabolically active indicating the activation of cellular metaplasia. Feeding activity Morphology of healthy leaves triggers growth is host leaf, especially around the nymphal bed, thus making the gall recognizable. Alstonia scholaris leaves are simple, The abaxial epidermis of the leaf part petiolate, and verticillate at the node; they are accommodating the nymph responds actively by ovate to obanceolate, length 5to 15 cm and producing hypertrophy and hyperplasia. Later on, breadth 4to 6 cm, narrow at the bases, entire, mesophyll cells also join hyperplasia and thus coriaceous, rounded or blunty acumunate at the contribute to the labial growth around the nymph. apex. Upper surface is dark green, glabrous while In 3-5 days, labial growth encloses the nymph. lower surface is rather pale and covered with whitish bloom. Midrib is prominently raised and Histology of mature gall the lateral nerves are 50 to 60 in number, close to each other, nearly horizontal and parallel.In In mature gall the epidermal layer consist transverse section view, the shape of the midrib relatively narrow and more elongated cells, with appears as Plano convex with flat adaxial side and the reduction in the stomatal frequency. Near the hemispherical abaxial side. The adaxial epidermis base of gall, especially immediately below the consists of large thick walled, barrel shaped cells surface, the palisade and spongy tissues are covered with thick striated cuticle. The abaxial conspicuously hypertrophied. These result in epidermis is papillae and comparatively of smaller much elongation of both the type of tissues. A cells. The papillose are tall and variable in shape. layer of sclerenchymatous cell develops The stomata are sunken and exclusively to the surrounding the pear shaped gall cavity which lower surface. The hypodermis is of single layered opens through an ostiole on the dorsal side of the and placed on adaxial surface of the leaf. The leaf. Intercellular spaces in between spongy mesophyll consists of palisade and spongy tissues. parenchyma are much reduced. Towards the The palisade in 1-2 layers and spongy tissue is of apices and in the neighborhood of the gall cavity loosely arranged cells. Vascular bundles are the cells are undifferentiated, large, rounded bicollateral and extend through mesophyll and are parenchymatous. Vascular supply is less xylem strand surrounded by phloem on both sides. disorganized by the division of xylem and phloem parenchyma cells and vascular bundle are

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Studies on the histomorphology of leaf galls on Alstonia scholaris L. (Apocynaceae) induced by Pauropsylla tuberculata Crawford.

Table 1. Shape, Size and Type of Galls.

Days Stages of instar in the Types of gall Shape of gall Avg. Size of gall Opening gall (mm) 1st and N1 Newly formed Pimple like elevation 1.1 1.0 Absent 2nd 5th N2 Young Small globular 1.8 1.5 Absent

7th N2 (late 2nd nymphal Young Globular with smooth 3.2 2.7 Absent stage) surface 12th N3 Medium Globular with fine lines 4.1 3.6 Elevation of opening 18th N4 Mature Globular with sunlight 5.2 4.5 Elevation wrinkles of opening 24th N5 Old Globular with sunlight 5.8 4.6 Lacerated wrinkles opening before emergence 30th Empty gall stage Old Globular with wrinkles 5.8 4.6 opened and cracks Average has been taken of 50 observations

Table 2. Color Changes in the Developing Galls of P. tuberculata.

Days Stages of instars Types of gall Color of gall Opening in the gall 1st and 2nd N1 Newly formed Green Absent

5th N2 Young Green Absent

7th N2 (late 2nd Young Green Absent nymphal stage) 12th N3 Medium Pale green Elevation of opening 18th N4 Mature Almost yellowish Elevation of opening 24th N5 Old Almost yellowish Lacerated opening before emergence

30th Empty Old Brownish Opened

Average has been taken of 50 observations scattered irregularly in gall parenchyma. The Histology of old gall number, size and shape of chloroplast in the infested galls tissue are markedly reduced as With the growth and development of compared to healthy. nymph inside gall, mesophyll region of the gall

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Om Datta and S.C. Dhiman and gall volume rapidly increases. The number of The first visible change is a slight discoloration on layers between the adaxial epidermis and nymphal the area where the eggs are deposited by female P. chamber increases to nearly 15, composed of tuberculata. Chemical stimulus brings about compactly arranged parenchyma cells. degeneration of surrounding cells forming a small Hyperplasia in the palisade cells is very distinctly cavity within which the egg lies. Gradually the observed. Hypertrophy followed by hyperplasia decolorized area increases in size and forms a takes place and bring about elevation by repeated small outgrowth on an adaxial side of the leaf but anticlinal division. The palisade cells gradually are later on its growth is towards the adaxial side. A replaced by thin walled compactly arranged little bulge appears on the adaxial side of the parenchyma and gradually lose the chloroplast. leafwhich further develops in to a dome shaped The hypertrophied cells appear large, round and structure. The psyllid galls as a whole are highly compactly arranged. Concurrently with the diverse in gall shape and galling position, P. increase in gall volume the nymphal chamber, too, tuberculata makes pouch galls on the leaves of A. increase in volume offering adequate space to the scholaris. The mature epiphyllous pouch galls are rapidly- growing nymph. The nymph feeds on the unilocular with a single cavity or multilocular with parenchyma cells of the gall wall that lie either 3-8 cavities. The mature gall is monothalamus close to itself or at a depth of 6-10 cells. subcylindrical, concolours with the host leaf, Following the moulting to fifth instar, the gall except at the apex which is yellowish. The wall is attains its final shape including the prominent thick and succulent. The cavity is subcuneate with conical covering growth along the abaxial side and the sharp edge pointing distal end. The galls distinct bulge along the adaxial side of the host appear multilocular because the adjacent galls leaf. With further lysis of the cells the chamber coalesce. increases in size and the nymphal stages are complete. The cells undergoing lysis appeared Shape, size of young, mature and old galls compressed and deformed. Because of the rapid increase in the mass and linear dimensional The shape of mature gall is observed values, the nymph has just enough space in semiglobose, globose, conical and glabrous. A nymphal chamber. Characteristically, at this stage newly formed gall looks like a small pimple on the of development, the nymph shifts its feeding site leaf and it measures hardly 1.0 to 5mm in from parenchyma cells to vascular phloem. The 5th diameter. Size of gall variesupon the growth and instar nymph comes out through the newly formed stages of nymph harboring in it. With the lacerated opening (0.3-1mm) on the adaxial side developing stages of P. tuberculata nymph, size of of the cavity or more often on abaxial side. The the gall also increases. After nymph approaches whole gall appears to be fleshy. Lining the 3rd instar stages, a very slight increase in the size chamber a periderm like layers is formed. The gall of gall take place. This increase in size occur up to tissues remain alive for some weeks after the 4th instar stage. A matured gall at the tip was emergence of 5th instar. Later on, the gall tissue measured about 2.5mm in diameter and 3mm at disintegrates but the periderm remains almost base. Depending upon the maturity of gall, the intact until leaf abscission. diameter of gall chamber ranges from 0.5-2mm. In heavy infestation condition galls fuses to form Structure and type of galls agglomerated mass and entire leaf turned gallinaceous and size of this agglomerated mass Initiation of the gall formation results was observed about 6-12 mm. At the time of from the oviposition on leaves by P.tuberculata. emergence, mature fifth instar nymph emerges out International Journal of Agricultural Invention 1(1): 2016 68

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Studies on the histomorphology of leaf galls on Alstonia scholaris L. (Apocynaceae) induced by Pauropsylla tuberculata Crawford. through small circular lacerated opening in the wrinkles shrink slightly due to drying and death of center of the gall. An empty gall develops more gall tissue. (Table 1).

Table 3. Number of Galls and Infestation Percentage.

S.N. Study Areas Total no. of Total no. of % of Avg. No. Avg. no. Avg. no. of leaves per infested infestation of galls of branch galls per branch leaves per per per plant plant branch branch 1 Saharanpur 43 38 88 2660 46 87780 proper 2 Kalsia 42 31 74 2170 59 73780 3 Behat 41 33 80 2370 61 80850 4 Shakumbhari 38 28 74 1960 60 62720 Devi 5 Bihari garh 36 30 83 2100 52 63300 6 Nakur 32 26 81 1820 60 65520 7 Punwarka 43 31 72 2170 58 96800 8 Baliyakheri 32 27 84 1890 57 62370 9 Chilkana 38 29 76 2030 62 73080 10 Chhutmalpur 37 27 87 1890 64 71820 11 Deoband 33 26 79 182062 62 61880 12 Nagal 33 20 63 1400 53 50400

Color changes in developing galls of this part receives minimum exposure to sun light. Galls occurred on entire leaf surface but on Newly formed gall having N1 and N2 are the top it rarely observed. Maximum number of green in color but as the gall develops its color galls is being near the midrib and side veins changed to pale green. Later on it appears almost because these parts first get rich water and food yellowish in color. Mature gall contains a supply. Average data taken of 50 observations of lacerated opening on the lower surface of the gall. leaves showed that maximum number of galls per The empty gall soon turns into brown color which leaf was 151 and minimum were 1 gall per leaf. gradually become hard and woody (Table 2). However, on agglomerated leaf counting of galls becomes very difficult. After cutting hand sections Number of galls per leaf and per plant of agglomerated mass, number of gall on such leaf was counted. The maximum numbers of galls Number of galls per A. scholaris tree occur in August to October, when temperature and depends upon the age of tree as well as on the size humidity remain suitable for growth and of canopy. On mature tree, maximum number of development of insect P. tuberculata. Minimum galls were found in the middle area of the tree number of galls occurs from March to June due to foliage, while minimum number of galls have increase in temperature and decrease in been observed in east, west and south part of tree humidity.In Saharanpur district, at different foliage because it gets proper sunlight which is localities, number of galls per plant varied necessary for photosynthesis and development of from50400 to 87780; maximum being at Behat foliage on the tree. Very few galls have been road and minimum at Nagal Table 3 it was further observed in north direction of tree because foliage observed that maximum number of gall occurs on

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Om Datta and S.C. Dhiman Om Datta and S.C. Dhiman

those A. scholaris , which were situated in induced leaf galls on economically important open areas, exposed to direct sunlight. Minimum plants in Rajasthan, India. Bioscience Discovery, 2 galls occur on those which were situated in (3), 345-347. shadow area surrounded by other plant species. Johnson, D. A. (1940) Plant Micro techniques. Mc REFERENCES Graw Hill, New York, pp-523.

Dhiman, S.C. and Kumar, D. (2013) Impact of Mani, M. S. (1973) Plant Galls of India (1st ed.). gall formation on Alstonia scholaris L. Mac Millan India, New Delhi, pp-323. (Apocynaceae) tree induced by Pauropsylla tuberculata Crawford (Homoptera-Psyllidae), Sass, J. E. (1951) Botanical mircotechniques. 2nd Proc. of Nat.Sem. on Relevance of Traditional ed. The Town State College Iowa, pp-115. Areas of Biological studies in Modern Context, published by Deptt.of Zool. Janta Vedic College, Srilakshman, P., Sailja, D. Bhanuteja M., Kumar, Baraut, pp- 11-16. D. R, and Madhuri M., (2012) Quantitative estimation of carbohydrates in insect induced and Gupta, J. P. (2011) Enzyme involved in phenol fungal infected leaf galls of pongamia pinnata. Int. metabolism of gall and normal tissues of insect J. Plant Animal and Env.Sci.2 (2), 203-205.

Manuscript received on Feb 27, 2016, Accepted for publication on March 29, 2016

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