analysis of morphological traits in different host plants associated with resistance to phenacoccus...

7/28/2019 Analysis of morphological traits in different host plants associated with resistance to Phenacoccus solenopsis- an invasive pest in Pakistan

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African Journal of Biotechnology Vol. 11(97), pp. 16330-16335, 4 December, 2012Available online at http://www.academicjournals.org/AJBDOI: 10.5897/AJB12.363ISSN 16845315 2012 Academic Journals

Full Length Research Paper

Analysis of morphological traits in different host plantsassociated with resistance to Phenacoccussolenops is-

an invasive pest in Pakistan

Muhammad Rafiq Shahid1,2*, Muhammad Jalal Arif1, Muhammad Aslam Khan1,Amjad Ali2, Anjum Suhail1, Muhammad Shahid Iqbal2, Muhammad Javaid1, Rehana

Bibi1, Asif Shehzad1, Azhar Abbas Khan3 and Arif Muhammad Khan4

1University of Agriculture, Faisalabad, Pakistan.

2Ayub Agricultural Research Institute, Faisalabad, Pakistan.

3Department of Entomology, University of Sargodha, Sargodha, Pakistan.4National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan.

Accepted 12 April, 2012

Phenacoccus solenopsisTinsley (Pseudococcidae: Hemiptera) is a sucking insect pest and ispolyphagous in nature. Twenty five (25) different host plants were screened against P. solenop sisandtheir physicomorphic traits were determined to correlate their role against pest population. Among thetested plant species, most favorable host plants of mealy bug on the basis of population wereGossypium hirsutum(69.7410.5), Solamummelongena(62.4110.0), Helianthus annuus(61.8310.0),Hibiscus rosa-sinensis(61.110.0) and Lantana camara(55.839.75), but the least preferred plants weretandla Digera arvensis(1.571.00) and Conyza bonariens is(3.831.75). Significant variations wereobserved in all the morphological plant characters recorded from different plant species. The maximumleaf thickness per plant was 2.040.23 m in plant species S. melongenawhile minimum thickness of

leaf was recorded from lehli (0.250.02 m). Maximum trichome density per plant was 44472.4 insunflower followed by 411.619.6, 39952, 391.622.0, in C. bonariensis, AbelmoschusesculentusandWithania somni ferarespectively but minimum were 2.331.45 in Chinopodium mo rale, followed by2.661.4, and 32.08 in Portulacaoleraceaand Trianthemaportulacastrumrespectively. The maximumhair length per plant (2.620.07 mm) was of sunflower followed by 2.550.03 mm in okra, 2.530.06 mmin both S. melongenaand G. hirsutum. It was concluded that plant characters including trichomedensity and hair length favor mealy bug population showing r-values of 0.357* and 0.190 respectivelybut leaf size and leaf width (leaf area and leaf thickness) exerted negative effect on pest populationshowing r-values of -0.172 and -0.285 respectively.

Key words: Phenacoccussolenopsis, invasive species, physicomorphic traits, resistance.

INTRODUCTION

Phenacoccus solenopsis was originally discovered inU.S.A. by Tinsley (1898) on cotton and was consideredas a minor pest of cotton until 1990 (Ben-Dov, 2008). Itattained invasive status when reported from othercountries. In Chile, from 1995 to 1997, it was seen as a

*Corresponding author. E-mail: [email protected]. Tel:92-333-6013710. Fax: 92-41-2651437.

pest of Papino (Solanum muricatum Aiton, Solanaceae)in Brazil, as a pest of tomato (Lycopersicon esculentumMiller, Solanaceae) (Culik and Gullan, 2005), and inPakistan, it was reported in 2005 as a pest of cottonThen, in India, cotton mealy bug (CMB) was reportedfrom almost all the cotton-growing centres of India(NCIPM, 2008). The incidence and severity of the CMBoutbreak in the Indian Punjab was worst in villagesadjoining the Pakistan boundary (Yousuf et al., 2007Saini and Ram,2008) and Haryana (Mongaetal.,2008),


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where the infestation consisted of a mixture of species,mostly P. solenopsis and Meconellicoccus hirsutus(Monga et al., 2008). P. solenopsis has had a devastatingimpact on cotton production in India (NCIPM, 2008;Nagrare et al., 2009), in Thailand on vegetables (USDA,2008; Bambawale, 2008; Hodgson et al., 2008; Tanwar

et al., 2007), in Nigeria on Hibiscus rosa-sinensis L.(Dicotyledones: Malvaceae) (Akintola and Ande, 2008)and most recently, P. solenopsis was reported to be apotential pest in 17 provinces of the Peoples Republic ofChina (Wang et al., 2009). It has also been reported inColombia (Kondo et al., 2008).

Based on this information, incidence of P. solenopsison cotton is reported mainly from Pakistan (FBS, 2008)and India (Goswami, 2007). Its invasion in Pakistan andIndia is a great threat to cotton industry; intensity of pestremained higher in Pakistan as compared to India,because mealy bug devastated 60728.74 ha of cottonarea across Pakistan (Muhammad, 2007), but nearly809.7 ha in India (Goswami, 2007). Other than cotton, themealy bug has been recorded to feed on 154 plant spe-cies belonging to 53 families, these host plants serve ascarriers of pest to the main crop and provide feeding linkthroughout the year (Abbas et al., 2010).

Population of pest varies from plant to plant and maybe due to external or internal physiology of the plant. Thisis because plants have the ability to alter the behavior offeeding insect (Karban and Baldwin, 1997) throughaccumulation and excretion of toxic exudates or hostplants which create hindrance against insect pest due tomorphological traits (Stadler, 2000; Hirota and Kato,2001; Goncalves-Alvim et al., 2004), because thick waxycuticular layer works as a defense against herbivory

insect pests (Taiz and zeiger, 1998). These featuresimpair the normal feeding or oviposition of insect pests(Morris and Dwyer, 1997; Underwood, 1999). This infor-mation is essential for understanding the morphologicalmechanisms underlying the resistance. In Pakistan, workdone in this regard is still quite sketchy and needs moreextensive research. Thus, owing to the lack of informationon this side, the present study was undertaken to find outthe relationship between the P. solenopsis populationand morphological traits of different host plants.

MATERIALS AND METHODS

The study was conducted to investigate the role of morphologicaltraits of various host plants against cotton mealy bug (P. solenop-sis) at University of Agriculture, Faisalabad, during 2007 to 2008.

Tested plant material

A total of 25 host plant species viz., Lantana (Lantana camara)Verbenaceae, Krund (Chinopodium morale) Chenopodiaceae, chi-nese rose (Hibiscus rosa-sinensis) Malvaceae, Lehli (Convolvulusarvensis) Convulvulaceae, peeli dhodak (Launea nudicaulis) Eup-horbiaceae, Aksun (Withania somnifera) Solanaceae, Jangli-haloon(Coronopusdidimus)Brassicaceae,Hazardani(Euphorbiaprostrate)

Shahid et al. 16331

Euphorbiaceae, Loosen booti (Conyza bonariensis) AsteraceaeBrinjal (Solamum melongena) Solanaceae, Okra (Abelmoschusesculentus) Malvaceae, Leh (Cirsium arvense) Asteraceae, Bathu(Chenopodium album) Chenopodiaceae, Cotton (Gossypiumhirsutum) Malvaceae, Chilli (Capsicum frutescens) SolanaceaeCholai (Amaranthus spinosus) Amaranthaceae, Gardenia (Clerodendron inerme), Itsit (Trianthema portulacastrum) AizoaceaeQulfa (Portulaca oleracea) Portulacaceae, Bakhra (Tribulus terrestris) Zygophyllaceae, Tandla (Digera arvensis) Amarantha-ceaeDaryaibooti (Eclipta prostrate) Asteraceae, Parthenium (Partheniumhysterophorus) Asteraceae, Puthkanda (Achyranthes asperaAmaranthaceae and Sunflower (Helianthus annuus) Asteraceaewere screened against cotton mealy bug during the cotton growingseason of 2008 to 2009. Population of cotton mealy bug wascalculated from a specific biomass as done by Abbas et al. (2010).

Physio-morphic plant character studies

These plant species were further studied in details for morphological characters for resistance against P. solenopsis (Tinsley)Morphological traits of the selected plant species were studied atIntegrated Pest Management Laboratory, University of Agriculture

Faisalabad, Pakistan, during the same season. For this purposefully mature leaves of tested plant species were selected for thestudy of the thickness of leaf lamina (m), trichome density fromleaf lamina (per cm

2), as well as length of hair (mm) from the lowe

side of the leaf. By using Stereoscope binocular microscope, theobservations were taken from three different places, whereas, leafarea was determined by using leaf area meter and reading of threeobservations were averaged for further statistical analysis.

Statistical analysis

The data was analyzed statistically using Statistical Package 5.5 tofind the significance of the results within the host genotypes. Meanswere compared by Duncan multiple range (DMR) test at 5%probability by using Statistical Package 5.5. Pearsons correlation

(r) coefficient and stepwise regression analysis was calculatedbetween mealy bug population and morphological characters oplant in order to observe the role and contribution of morphologicatraits of tested plants in exhibiting resistance to the pest.

RESULTS

Susceptibility of tested plant species to cotton mealybug (Phenacoccus solenopsis)

The mealy bug population among tested host plantsduring cotton growing season is presented in Table 1The plant species arranged in descending order with res-pect to mealy bug population indicate that plant species

viz., cotton, brinjal, sunflower, Chinese rose and lantanaappeared to be highly susceptible in harboring maximumpopulation of the pest, but leh, peelidhodak, bathu, janglihaloon, loosenbooti and tandla expressed resistance thahad lower mealy bug population (Table 2). All other tes-ted plant species showed intermediate response againstmealy bug.

Morphological plant characters

Significant variations were observed in all the morpholo


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16332 Afr. J. Biotechnol.

Table 1. Analysis of variance regarding susceptibility of host plants against Phenacoccussolenopsis during 2008 to 2009 at Punjab, Pakistan.

Source d.fMean square

*TD *HL *LT *LA

Plants species 24 88347.35 0.51 0.68 2335.31

Error 50 1754.94 0.015 0.012 30.08Total 74

*TD: Trichome density; *HL: hair length; *LT: leaf thickness; *LA: leaf area.

gical plant characters recorded from different plantspecies with trichomedensity (F= 50.34; df=24; p


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Shahid et al. 16333

Table 2. Susceptibility of plant species to Phenacoccus solenopsis Tinsley during 2008 to 2009 at Punjab, Pakistan.

PlantMealy bug

(Number)

Leaf thickness

(m) S.E

Leaf area

(cm2) S.E

Hair length

(mm) S.E

Trichome density

(Number) S.E

Cotton 69.7410.5a

1.330.05bc

33.54.13cde

2.530.05ab

37543.3a

Brinjal 62.4110.0ab

2.040.23a

68.78.53b

2.530.06AB

875.2bc

Sunflower 61.8310.0ab 1.400.02bc 120.43.2a 2.620.07a 411.619.6a

Chinese rose 61.110.0ab

1.820.07ab

37.91.27cd

1.70.14defg

14.34.8c

Lantana 55.839.75ab

0.710.04def

17.11.18def

2.460.09abc

380.617.9a

Lehli 49.088.2b

0.250.028f

1.60.05ef 1.830.13cdefg

11.332.02c

Aksun 45.088.0b

1.30.05bc

19.91.78def

2.230.02abcd

391.622.0a

Mohabat booti 44.087.5b

1.230.04cd

60.010.9bc

2.230.06abcd

252.648.9ab

Cholai 41.65.5b

0.860.04de

14.00.48def

2.110.05abcde

f 14.63.38c

Chili 40.915.5bc

1.360.05bc

9.61.38def

1.530.14efg

3.332.02c

Itsit 38.415.2bc

1.720.05abc

0.50.04ef

1.6060.04defg

32.08c

Okra 36.65.15bc

1.100.06cd

25.43.9def

2.550.03ab

39952a

Qulfa 34.165.1bc

1.780.03ab

0.440.034f

1.380.04g

2.661.4c

Hazardani 28.164.5c

1.330.04bc

0.10.01fg

1.510.05fg

8.661.2c

Bakhra 26.084.5c

0.720.02def

3.30.63ef 2.420.05abc

29130.2ab

Gardenia 24.494.5c

0.790.04def

14.51.12def

1.90.05bcdefg

204.9c

Daryibooti 20.494.25c

0.890.02de

0.60.04ef

2.170.04abcde

28.668.2c

Puthkanda 14.834.05cd

1.000.04cd

1.470.19ef

2.270.06abcd

25.664.8c

Krund 11.414.00d

0.370.025ef

7.00.76ef

1.440.05g

2.331.45c

Leh 10.743.75d

1.310.04bc

12.80.86def

1.830.04cdefg

13.36.0c

Peelidhodak 7.083.55de

0.610.06def

17.21.16def

1.960.02abcdefg

5.332.0c

Bathu 6.412.5de

1.170.06cd

6.40.26Ef

1.450.02fg

14.61.4c

Janglihaloon 4.742.0de

0.340.03ef

0.030.006g

2.420.04abc

22.36.35c

Loosenbooti 3.831.75de

0.680.02def

0.80.04ef

2.460.09abc

44472.4a

Tandla 1.571.00e

0.840.04de

4.450.51ef

1.640.05defg

84.3c

Mean followed by same letter(s) in a column are not significantly different by DMRT P = 0.05.

bug was maximum on cotton, brinjal, sunflower, Chineserose and lantana. These findings are in agreement to thefindings of Ben-Dov et al. (2008) and Aheer et al. (2009)who had similar results. The information regarding maxi-mum prevalence ofP. solenopsis on Chinese rose (Hibi-scus chinensis), okra (Abelmoschus esculentus (L.),Malvaceae), sunflower (Helianthus annuus L., Compo-sitae), brinjal (Solanum melongena L., Solancaeae),tomato (Lycopersicon esculentum) and other weedsthroughout the year in Pakistan was shared in popular

articles for the awareness of all concerned (Abbas et al.,2007). Another study documented all the hosts (154species) on which cotton mealy bug was found inci-dentally or in low, medium or high intensity in the agro-ecological conditions of Multan, Pakistan (Arif et al.,2009).

The results of this study revealed that population ofcotton mealy bug among tested plant species was varia-ble due to host plant mechanisms particularly mor-phological factors which contribute significantly towardshost plant resistance, which is an important component ofpest management. The indication of resistance against

insect pest and diseases is measured either by the occurrence of a population of insect pests on the plantobserving damage due to feeding and oviposition or byproviding plants for overall development of offspring(Abrahamson and Weiss, 1997); however, insect selec-tion and utilization of a host plant depends upon bothbiophysical and biochemical factors (Bernays and Chapman, 1994). The additive effects of these factors enablethe plants to provide barrier to normal feeding or byrepelling insect pests via volatile exudates (Van- Emden

and Peakall, 1996).Although none of the tested plant species were repor-

ted as immune, they have low pest population progresswhen compared to susceptible host plants. The studyconfirms that plant species tandla and loosenbooti arehighly resistant to cotton mealy bug (P. solenopsis)These results are in partial agreement with the findings oHeng-Moss et al. (2002) who screened buffalo grassgermplasm Cody, Tatanka, Bonnie Barae, NE91-118

Against chinch bug, Blisus occiduus and reported thaNE91-118 possessed resistance against pest. Based onthe present results, a positive association was observed


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16334 Afr. J. Biotechnol.

Table 3. Correlation studies between Phenacoccus solenopsis and morphological traits of plants at Punjab, Pakistan.

Variable Cotton mealy bug Hair density Hair length Leaf thickness Leaf area

Cotton mealy bug 1.000

Hair density 0.357* 1.000

Hair length 0.190 0.742** 1.000

Leaf thickness -0.285 0.008 -0.113 1.000Leaf area -0.172 0.459* 0.460* 0.413* 1.000

** Correlation is significant at the 0.01 level; *correlation is significant at the 0.05 level.

Table 4. Step wise regression ofPhenacoccus solenopsis and morphological traits of plants atPunjab, Pakistan.

Regression model Overall effect Individual effect

Y1=26.38+0.044X1 12.71 12.71

Y2=41.58+0.059X1 -8X2 13.95 1.24

Y3=64.47+0.067X1-13X2-14.1X3 23.75 9.8

Y4=48.69+0.073X1-7X2-7.7X3-0.24X4 29.27 5.52

X1: Trichome density; X2: HAIR length; X3: leaf thickness; X4: leaf area.

between hair density and hair length to mealy bugpopulation; results are supported by Johnson-Cicalese etal. (1998) who found that mealy bug damage ratingswere positively correlated with pubescence level becausehairs may provide foothold for early instar mealy bugs,whereas leaf thickness, leaf size and leaf width res-ponded negatively with mealy bug population. Theseresults are in partial agreement with Baker et al. (1981),Reinert (1982), Smith et al. (1994) and Heng-Moss et al.

(2002) who suggested that plant defenses result inreduced oviposition, extended life cycle and pest morta-lity. The morphological factors influence the nutritionand/or ovipostion of the pest-insects by limiting theamount of feeding and/or oviposition (Dhaliwal and Arora,2003). These mechanisms of resistance have proved tobe effective tools against the insect pests in many cropsand vegetables (Eigenbrode and Trumble, 1994; Johnson- Cicalese et al., 1998; Smith et al., 1994; Felkl et al.,2005). However, Bartlett and Clancy (1972) stated thatan integration of chemical, biological and mechanicalcontrol is essential for long-term management of mealybugs.

Conclusion

P. solenopsis is a polyphagous insect pest. Among testedhost plants, the most favorable host plants of mealy bugare cotton, brinjal, sunflower, Chinese rose and lantana,but the least preferred plants are tandla and loosen booti.Plant characters including trichome density and hairlength favor mealy bug population but leaf size, leaf widthand leaf thickness exert negative effect on pest popu-lation.

REFERENCES

Abbas G, Arif MJ, Ashfaq M, Aslam M, Saeed S (2010). Host plantsdistribution and overwintering of cotton mealybug (Phenacoccussolenopsis; Hemiptera: Pseudococcidae). Int. J. Agric. Biol. 12: 421

425.

Abbas G, Arif MJ, Ahmad (2007). Kapas ki mealybug keliey Ihtiattadabeer wa Iqdamat. (The precautionary measures andmanagement strategies for cotton mealybug) (In Urdu.) Express, 14

Apr. 2007. p. 15.Abrahamson WG, W eiss AE (1997). Evolutionary ecology across three

tropic levels: goldenrods, gallmakers, and natural enemies. PrincetonUniv. Press, New Jersey, USA.Aheer GM, Shah Z, Saeed M (2009). Seasonal history and b iology o

cotton mealy bug, Phenacoccus solenopsis Tinsley. J. Agric. Res

47(4): 423-431.Akintola AJ, Ande AT (2008). First record ofPhenacoccus solenopsis

Tinsley (Hemiptera: Pseudococcidae) on Hibiscus rosa-sinensis in

Nigeria. Agric. J. (Pakistan) 3: 1-3.Arif MI, Rafiq M, Ghaffar A (2009). Host plants of cotton mealy bug

(Phenacoccussolenopsis): A new menace to cotton agro ecosystem

of Punjab, Pakistan. Int. J. Agric. Biol. 11: 163-167.Baker PB, Ratcliffe RH, Steinhauer AL (1981). Tolerance to hairy chinch

bug Blisus Leucopterus feeding in Kentucky bluegrass (Poa

pratensis). Environ. Entomol. 10: 153-157.Bambawale OM (2008). Phenacoccus solenopsis, the main mealybug

species on cotton in India does not appear to be invasive. An online press release by Director, NCIPM, New Delhi, 19 May 2008

Available on-line ahttp://www.ncipm.org.in/Mealybugs/NoninvasivePhenacoccus_solenopsis.pdf (verified 26 Jun. 2009).

Bartlett BR, Clancy DW (1972). The Comstock mealybug in Californiaand observations on some of its natural enemies. J. Econ. Entomol65(5): 1329-1332.

Ben-Dov Y, Miller DR, Gibson GAP (2008). ScaleNet: A SearchableInformation System on Scale Insects. Available online:http://www.sel.barc.usda.gov/ scalenet/scalenet.htm.

Bernays EA, Chapman RF (1994). Host-plant selection byphytophagous insects. Chapman and Hall, New York.

Culik MP, Gullan PJ (2005). A new pest of tomato and other records of

mealybugs (Hemiptera: Pseudococcidae) from Esprito Santo, BrazilZootaxa, 964: 1-8.
http://www.ncipm.org.in/Mealybugs/NoninvasivePhenacoccus_http://www.sel.barc.usda.gov/http://www.sel.barc.usda.gov/http://www.ncipm.org.in/Mealybugs/NoninvasivePhenacoccus_


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