REACTION OF RICE LANDRACES AGAINST BROWN PLANTHOPPER NILAPARVATA LUGENS STAL.

NSave Nature to Survive QUARTERLY 9(1&2): 605-609, 2015 (Supplement on Rice) REACTION OF RICE LANDRACES AGAINST BROWN PLANTHOPPER NILAPARVATA LUGENS STAL. G. M. DHARSHINI* AND D. K. SIDDEGOWDA Department of Agricultural Entomology, University of Agricultural Sciences, GKVK, Bengaluru - 560 065, INDIA e-mail: dharshinigmmahesh@gmail.com ABSTRACT INTRODUCTION The brown planthopper (BPH), Nilaparvata lugens Stal. (Hemiptera: Delphacidae)] is a typical piercing-sucking insect pest of rice (Oryza sativa L.), which feeds on phloem sap and thus affects the growth of rice and results in hopperburn. Furthermore, BPH also transmits viruses, such as the ragged stunt virus and grassy stunt virus, and associated diseases to rice plant. In recent years, BPH infestations have intensified across Asia, causing heavy yield losses in rice ecosystem. As the popular rice varieties are susceptible to plant hoppers, farmers depend solely on chemical pesticides for BPH management, which are expensive in terms of labour, cost and the environment. In addition, overuse of pesticides destroys the natural predators and leads to the insect developing resistance, which results in pest resurgence. So the most economical and environment-friendly strategy to control this insect is to identify and grow genetically resistant rice varieties. As a result there are several varieties resistant to BPH were developed and released for cultivation and they become susceptible to BPH within few years after their release. This is because of the development of N. lugens biotypes capable of surviving on and damaging resistant cultivars and it has been a constant threat (Pathak and Heinrichs, 1982). Identification of new donors and work out of their BPH resistance genetics is a continuous process to breed new BPH resistant varieties which can show resistance to newly evolved BPH biotypes (Balakrishna and Satyanarayana, 2013). Therefore, understanding of mechanisms of resistance, identification and deployment of new source for BPH resistance in modern high yielding varieties is the important strategy to reduce the yield loss. Traditional landraces of rice are the important reservoirs of valuable traits like medicinal properties, nutrition, taste, aroma, tolerance to drought and varying level of resistance to insect pests and diseases (Hanumaratti et al., 2008). In order to find the new source of resistance to BPH the present study was undertaken and focused on the evaluation of select landraces of rice to determine the mechanism of resistance and the results are herein reported. MATERIALS AND METHODS Glasshouse screening Two hundred and eight landraces were collected from different locations of Karnataka. These landraces were screened in the glasshouse against brown planthopper using modified seed beds (Sidde Gowda, 2009). Seed beds were filled with fertilizer enriched puddled soil. Rows of one meter length were drawn leaving 10 cm between rows. Ten rows of test entries were alternated with one row of susceptible check, TN 1. Thirty sprouted seeds of susceptible check TN 1 was sown in the two border rows. In the middle rows, 30 sprouted seeds of selected rice landraces were sown. When the seedlings were 8-10 days old, with 2-3 leaves, 2 nd instar Of 280 landraces screened, 22 entries were selected and compared for reaction against brown planthopper feeding. When compared to susceptible checks, all the landraces recorded to have increased days to wilt ranging from 31.88 to 47.77 days indicating level of tolerance to BPH feeding. The land races Ratna choodi 1 and Raibhog showed high level of resistance with reduced percentage of nymphal survival (18.33 %). As a indication of antixenosis or non preference landraces showed to contain reduced number of eggs compared to susceptible check. Among the landraces, Honasu and Kottayam recorded to contain 96.66 and 103.00 eggs with increased percent of unhatchability of eggs. Feeding preference of BPH for each landraces measured as honeydew excretion area showed that least number of excretion spots were observed in Rajamudi(5.00), Ratnachoodi 1(5.33) and JBT 36/14 (5.33). These landraces with different mechanism of resistance to BPH are possible source for developing resistant varieties. KEY WORDS Resistance Nilaparvata lugens Land races Received : 14.12.2014 Revised : 08.01.2015 Accepted : 27.05.2015 *Corresponding author 605

G. M. DHARSHINI AND D. K. SIDDEGOWDA BPH nymphs were released in the seed beds and it was ensured that each seedling had 6-8 nymphs. When 90 per cent of the plants of the susceptible check TN1 were killed, damage score for entries was recorded. The observations on BPH populations were also recorded at different days after release. The criteria followed for scoring the damage of individual plants was as per standard evaluation system developed by International Rice Research Institute (IRRI), Phillipines (Anon. 2002) Nymphal survival Two germinated seeds were planted in each pot and only one healthy seedling was retained after 5-6 days. For each variety, seedlings were raised in three pots. The plants were covered with mylar tubes with ventilating windows. Ten one day old nymphs in the mylar cage were released to fifteen days old plants and the open end of the tube was covered with a muslin cloth and tied with a rubber band. (Soundararajan et al., 2003). The plants were observed daily and the number of nymphs that reached adulthood were counted and removed them from the plant. The percent nymphal survival was calculated by Number of emerged % Nymphal survival ={ adults Number of }X 100 released nymphs Days to wilting The seeds were soaked and the germinated seedlings were sown in 500 ml plastic pots filled with fertilizer enriched puddled soil. Two germinated seeds were planted in each pot and only one healthy seedling was retained after 5-6 days. For each variety, seedlings were raised in 8 pots. Each pot served as a replication. The plants were covered with mylar tubes with ventilating windows. Twenty five, 2 nd instar nymphs were released in the mylar cage on fifteen days old plants and the open end of the tube was covered with a muslin cloth and fastened with a rubber band. The plants were observed daily for their health. The number of plants wilted with all leaves dried and per cent plants wilted was recorded. The experiment was terminated at 50 days after the release of nymphs and recorded the number of plants that did not wilt at the end of the study were also recorded and documented (Velusamy et al., 2006). Oviposition preference test Two germinated seeds were planted in each pot and only one healthy seedling was retained after five-six days. For each variety, seedlings were raised in six pots. Thirty day old plants were covered with mylar tubes with ventilating windows. One gravid female (seven days old) was released with the help of an aspirator in the mylar cage and the open end of the tube was covered with a muslin cloth and tied with a rubber band. The females were removed five days after release. The plants were observed for nymphal hatching. The number of hatched nymphs were recorded and removed from the plant. After all the eggs were hatched or when nymphs stop coming out (after 15-20 days of adult release) the plants were cut at the base and examined under stereo binocular microscope, total number of egg masses and number of unhatched eggs were recorded. Unhatched eggs were expressed as percentage of total, which is sum of number of nymphs counted and the number of unhatched eggs (Velusamy et al., 2006). Number of unhatched eggs % Unhatched eggs ={ }X 100 (Number of nymphs +Number of unhatched eggs) Adult feeding as indicated by quantity of honeydew excreted For each variety, seedlings were raised in three pots. Each pot represented a replication. Feeding rates on the test entries were determined by measuring the amount of honeydew excreted by N. lugens adults on 30 days old plants in feeding chamber described by Paguia et al. (1980). One day old 15 BPH females starved for two hours were released into the chamber and allowed to feed for 24 hours. When the honeydew excreted by BPH come in contact with the filter paper spots with blue tinged margin were formed. Then the filter papers were taken out and the area of the spots were measured by graph paper method. The area of all the honeydew spots were traced on a millimeter square graph paper and the number of squares within the spots were counted. The area of all the honey dew spots were added and honeydew excretion was expressed as mm 2 per 5 females Functional Plant Loss Index (FPLI) due to BPH infestation in rice plants To study the level of tolerance on 30-day-old seedlings, 50 1 st instar nymphs were introduced onto each plant. When the plants started to wilt, they were collected along with their roots, washed thoroughly, air dried for 3 hours, then oven-dried at 70ºC for 60 hours and weighed. The functional plant loss index (FPLI) was calculated for all the landraces by using the following formula (Alagar et al., 2007). FPLI = 1-{ RESULTS Dry weight of BPH infested plants Dry weight of BPH uninfested plants }X 100 Screening for resistance Out of 280 landraces, 22 landraces showed varied level of resistance to BPH feeding. Of these 22 landraces, 10 landraces viz., Baiganmanji, Honasu 1, JBT 36/14, Kottayam, Manila, Nazarbatta, PS 339, Ratna choodi 1, Raibhog and Rajamudi recorded the damage score of 1, whereas five landraces viz., Anilamanil, Kalakolli, Ratnachoodi 2, Selamsanna and Moradde recorded the damage score of 3, three landraces (Akkalu 1, Honasu 2 and Mysore mallige) registered the damage score of 5 and Chinnaponni, Karpoorakeli, Ugibatta and Akkalu 2 recorded the damage score of 7 (Table 1). Nymphal survival The survival rate of BPH nymphs was significantly less on all the entries tested compared to the susceptible checks TN1 and Jaya. Thenymphal survival was ranged between 18.33 and 46.66 in test entries. Entries such as Raibhog (18.33), Ratnachoodi 1 (18.33), Kottayam (19.16), Rajamudi (20.33), 606

REACTION OF RICE LANDRACES PS 339 (21.66) and Ratnachoodi 2 (23.33) found to have least survival rate. Some of the landraces viz., Akkalu 1 (43.33), Chinnaponni (40.83), Karpoorakeli (46.66) and Ugibatta Table 1: Levels of resistance of landraces to brown planthopper, N. lugens Sl. No. Designation Mean population Damage of BPH per 10 plants score 1 Baiganmanji 75.00 1 2 Honasu 1 49.00 1 3 JBT 36/14 9.00 1 4 Kottayam 43.75 1 5 Manila 20.00 1 6 Nazarbatta 39.00 1 7 PS 339 30.75 1 8 Ratnachoodi 1 32.00 1 9 Raibhog 23.50 1 10 Rajamudi 54.00 1 11 Anilamanil 21.75 3 12 Moradde 56.25 3 13 Ratnachoodi 2 58.50 3 14 Selamsanna 44.75 3 15 Kalakolli 68.25 3 16 Akkalu 1 58.50 5 17 Honasu 2 56.25 5 18 Mysore mallige 65.25 5 19 Akkalu 2 45.50 7 20 Karpoorakeli 33.75 7 21 Ugibatta 24.50 7 22 Chinnaponni 18.75 7 23 PTB 33 48.75 1 24 TN 1 66.50 9 25 Jaya 65.25 9 (42.50) recorded highest nymphal survival and were on par with susceptible checks Jaya (49.16) and TN 1 (48.33) (Table 2). Days to wilting Days to wilt varied significantly among the landraces in comparision with resistant check PTB 33 and susceptible checks TN1 and Jaya. Among the landraces, PS 339 (47.77), Kottayam (47.55), Honasu 1 (47.55), Baiganmanji (46.88), Nazarbatta (46.77), Ratnachoodi 1 (46.44), Raibhog (46.33) and Rajamudi (46.33) recorded highest number of days to wilt and were on par with resistant check PTB 33 (49.00)(Table 2). Oviposition preference test Fecundity The number of eggs laid by BPH on different landraces varied significantly. Among the landraces, Honasu 1 (96.66) recorded lowest number of eggs and was on par with other landraces viz., Kottayam (103.00), Ratnachoodi 1 (106.66), PS 339 (108.66), Rajamudi (109.33), Selamsanna (110.66), Moradde (112.33) and resistant check PTB 33 (110.33). The susceptible checks Jaya (135.66) and TN1 (136.66) recorded highest number of eggs as compared to other landraces (Table 2). Unhatchability of eggs The resistant check PTB 33 accounted for highest per cent of unhatched eggs and differed significantly with all the other test entries. However, among the landraces, Kottayam recorded 52.1 per cent of unhatched eggs, followed by JBT 36/14 (51.03%), Mysore mallige (49.60), Honasu 1(48.65) and Nazarbatta (47.79). The susceptible check TN 1 and Jaya recorded 31.46 and 29.73 per cent unhatched eggs, respectively (Table 2). Table 2: Reaction of different landraces of rice in response to N. lugens feeding Entry name Days to wilt(a) Plants wilted Fecundity(A) Unhatchability Nymphal survival FPLI(%)(B) (%)(B) of eggs (%)(B) (%)(B) Akkalu 1 43.10(6.64) ef 100(89.96) b 123.66(11.16) cdefg 45.26(42.27) gh 43.33(41.13) fij 18.79(25.67) hij Akkalu 2 32.66(5.80) i 100(89.96) b 123.00(11.13) cdefg 33.59(35.41) p 38.33(38.24) fghi 25.61(30.37) klm Anilamanil 42.66(6.60) ef 100(89.96) b 117.66(10.89) bcdef 42.48(40.66) j 27.50(31.56) cde 11.28(19.62) bcdef Baiganmanji 46.88(6.92) bc 100(89.96) b 120.66(11.02) bcdefg 41.45(40.06) k 26.66(30.93) bcde 10.34(18.46) abcdef Chinnaponni 32.33(5.77) i 100(89.96) b 120.33(11.01) bcdefg 41.54(40.11) k 40.83(39.66) ghij 20.22(26.58) ijk Honasu1 47.55(6.97) ab 66.66(59.97) a 96.66(9.88) a 48.65(44.19) e 21.66(27.72) abcd 8.52(16.70) abcd Honasu2 35.44(6.04) h 100(89.96) b 131.00(11.48) efg 43.46(41.22) i 32.50(34.73) efg 16.39(23.87) ghi JBT 36/14 41.44(6.51) f 100(89.96) b 112.00(10.63) abcd 51.03(45.57) c 25.83(30.50) bcde 8.51(16.90) abcd Kala kolli 42.55(6.60) ef 100(89.96) b 123.33(11.14) cdefg 44.58(41.87) h 22.5(28.28) abcd 12.23(20.43) defg Karpoorakeli 31.88(5.73) i 100(89.96) b 130.33(11.45) defg 35.03(36.27) o 46.66(43.06) ij 23.91(29.26) jkl Kottayam 47.55(6.97) ab 77.77(66.46) a 103.0(10.19) ab 52.12(46.19) b 19.16(25.91) abc 6.09(14.25) a Manila 45.10(6.79) cd 100a(89.96) b 116.33(10.82) bcde 38.12(38.13) m 30.00(33.10) def 13.25(21.31) efg Mysore mallige 38.22(6.26) g 100(89.96) b 132.33(11.51) efg 49.60(44.75) d 36.66(37.16) fgh 14.13(22.06) fgh Nazarbatta 46.77(6.91) bc 77.77(66.46) a 113.66(10.70) bcde 47.79(43.72) e 25.83(30.50) bcde 6.66(14.90) a PS 339 47.77(6.98) ab 100(89.96) b 108.66(10.46) abc 52.40(46.36) b 21.66(27.63) abcd 7.01(15.27)l a Ratna choodi1 46.44(6.89) bc 88.88(78.21) ab 106.66(10.37) abc 45.30(42.28) gh 18.33(25.27) ab 7.68(15.99) abc Ratna choodi2 43.77(6.69) de 100(89.96) b 121.33(11.05) cdefg 40.36(39.43) l 23.33(28.82) abcd 12.04(20.11) cdefg Raibhog 46.10(6.86) bc 100(89.96) b 117.00(10.85) bcdef 46.13(42.77) fg 18.33(25.27) ab 9.91(18.23) abcdef Rajamudi 46.33(6.88) bc 88.88(78.21) ab 109.33(10.50) abc 46.63(43.05) f 20.33(27.11) abcd 8.40(16.78) abcd Salam sanna 43.55(6.67) de 100(89.96) b 110.66(10.55) abc 43.38(41.18) ij 24.16(29.35) abcde 9.11(17.53) abcde Ugibatta 36.21(6.10) h 100(89.96) b 135.00(11.65) fg 36.08(36.90) n 42.5(40.66) hij 20.52(26.70) ijk Moradde 43.22(6.65) ef 88.88(78.21) ab 112.33(10.64) abcd 41.53(40.11) k 25.00(29.93) bcde 7.60(15.89) abc PTB 33 49.00(7.07) a 77.77(66.46) a 110.33(10.54) abc 55.86(48.34) a 15.83(23.42) a 5.97(14.06) a TN 1 29.33(5.51) j 100(89.96) b 136.66(11.73) g 31.46(34.10) q 48.33(44.02) j 30.98(33.81) m Jaya 27.66(5.35) k 100(89.96) b 135.66(11 69) fg 29.73(33.02) r 49.16(44.50) j 29.34(32.77) lm F -test * * * * * * *Significant at p=0.05. A=values in parenthesis are x+1 transformed values and B= values in parenthesis are angular transformed. 607

G. M. DHARSHINI AND D. K. SIDDEGOWDA Table 3: Honeydew excretion by BPH on different rice landraces Entry Name No. of spots Area (mm²) Akkalu 1 6.66 abcd 289.66 mn Akkalu 2 7.00 bcd 295.00 n Anilamanil 6.00 abcd 230.66 i Baiganmanji 5.66 abc 160.33 c Chinnaponni 7.33 cd 275.33 lm Honasu 1 6.00 abcd 171.33 cde Honasu 2 6.66 abcd 244.33 ij JBT 36/14 5.33 ab 190.66 fgh Kalakolli 7.00 bcd 295.00 n Karpoorakeli 7.66 d 323.33o Kottayam 6.00a bcd 163.00 cd Manila 7.33 cd 260.33 jkl Mysore mallige 6.66 abcd 271.66 kl Nazarbatta 6.00 abcd 201.33 h PS 339 6.33a bcd 143.00 ab Ratnachoodi 1 5.33 ab 178.33 def Ratnachoodi 2 6.00 abcd 198.66 gh Raibhog 5.66 abc 182.33 efg Rajamudi 5.00 a 157.33 bc Salam sanna 6.33 abcd 228.33 i Ugibatta 7.66 d 331.00 o Moradde 6.33 abcd 256.00 jk PTB 33 5.00 a 134.00 a TN 1 7.66 d 331.33 o Jaya 7.33 cd 350.33 p F -test * * *Significant at p=0.05. Means followed by same letter in each column do not differ significantly by DMRT Means followed by same letter in each column do not differ significantly by DMRT Functional Plant Loss Index (FPLI) due to BPH infestation in rice plants The FPLI due to BPH infestation was more in TN 1 (30.98%) and Jaya (29.34%) followed by Akkalu 2 (25.61), Karpoorakeli (23.91, Ugibatta (20.52), Chinnaponni (20.22%) and Akkalu 1 (18.79) while, the lowest FPLI was recorded in PTB 33 (5.97) followed by Kottayam (6.09), Nazarbatta (6.66), PS 339 (7.01), Moradde (7.60) and Ratnachoodi 1 (7.68) (Table 2). Adult feeding as indicated by quantity of honeydew excreted The least number on honey dew secreted spots 5 were observed in PTB 33 and Rajamudi followed by Ratnachoodi 1, JBT 36/14 and Baiganmanji with 5.33 mean number of spots. The feeding rate (as indicated by honey dew secreted area) was more on susceptible checks like TN 1 (331.33) and Jaya (350.33) as compared to resistant check PTB 33 (134.00). Among the landraces feeding rate was more on Akkalu1 (289.66 mm 2 ), Akkalu 2 (295.00), Kalakolli (295.00), Karpoorakeli (323.33) and Ugibatta (331.00), whereas less feeding rate was observed on Baiganmanji (160.33), Honasu 2 (171.33), Kottayam (163.00), PS 339 (143.00) and Rajamudi (157.33)(Table 3). DISCUSSION In the present study out of 280 landraces, 22 landraces showed varied levels of resistance to BPH. Off these, 10 landraces found to be resistant to BPH, whereas five landraces were found moderately resistant to BPH. The variation in the damage levels among the landraces might be due to inherent/ inbuilt character of the landraces, genetics and biochemical properties of the host plant. These findings were in agreement with the findings of Liu et al. (2009), who reported out of 515 rice landraces originating from Vietnam and China none was highly resistant to BPH (score 0), 23 were resistant (score 1 or 3) and 32 moderately resistant (score 5). In the present study resistant and moderately resistant landraces such as Anilam anil, Baigan mangi, Honasu 1, JBT 36/14, Kalakolli, Kottayam, Manila, Nazarbatta, PS 339, Ratnachoodi 1, Ratnachoodi 2, Raibhog, Rajamudi, Selamsanna and Moradde had increased days to wilt as a indication of level tolerance to BPH feeding. The least number of eggs laid on landraces indicated that the non-preference of landraces for oviposition by BPH and reduced nymphal survival rate and decreased adult feeding as indicated by quantity of honeydew excreted showed another mechanism of host plant resistance ie. Antibiosis. Similar observations were also made by Wu et al. (1986), Senguttuvan et al. (1991) and Alagar et al. (2007), wherein, they reported less number of eggs and higher per cent of unhatched eggs on PTB 33 as compared to susceptible check TN 1. Similarly, Bhanu et al. (2014) and Paguia et al. (1980) recorded lowest feeding rate in resistant varieties. Likewise, Kim et al. (1998) reported less amount of honeydew excretion on resistant cultivars. As suggested by Kumar et al. (2013), more genetic variability exhibited by Indian and exotic germplasms can be made use in selection for various agronomic traits. Similarly variable resistance trait observed in rice land races could be used in selection for Brown planthopper resistance In the present study, an attempt was made to identify the different mechanism of resistance in landraces. The rice landraces exhibited different levels of tolerance, antixenosis and antibiosis and the same can be used as potential source of resistance in breeding programmes. REFERENCES Alagar, M., Suresh, S., Samiyappan, R. and Saravanakumar, D., 2007. Reaction of resistant and susceptible rice genotypes against brown planthopper (Nilaparvata lugens). Phytoparasitica. 35(4): 346-356. Anonymous 2002. International Rice Research Institute (IRRI)- standard evaluation system in rice, P. O. Box 933, Manila, Philippines. 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REACTION OF RICE LANDRACES variability of Indian and exotic rice germplasm in Allahabad agroclimate. The Bioscan. 8(4): 1445-1451. Liu, Y., Su, C., Jiang, L., He, J., Wu, H., Peng, C. and Wan, J. 2009. The distribution and identification of brown planthopper resistance genes. Hereditas. 146: 67-73. Paguia, P., Pathak, M. D. and Heinrichs, E. A. 1980. Honeydew excretion measurement techniques for determining differential feeding activity of biotypes of Nilaparvata lugens on rice varieties. J. Econ. Entomol. 73: 35-40 Pathak, P. K. and Heinrichs, E. A. 1982. Selection of biotype population 2 and 3 of N. lugensby exposure to resistant rice varieties. Environ. Entomol. 11: 85-90. Senguttuvan, T., Gopalan, M. and Chelliah, S. 1991. Impact of resistance mechanisms in rice against the brown planthopper, Nilaparvata lugens Stal (Homoptera: Delphacidae). Crop Prot. 10(2): 125-128. Sidde Gowda 2009. Screening of Rice germplasm against Brown planthopper, Nilaparvata lugens (Stal.) Paper presented in Annual meeting of Entomological society of America held at Indian apolis, USA from 12-16, December, 2009. Soundararajan, R. P., Chitra, N. and Gunathilagaraj, K. 2002. Evaluation of antibiosis resistance to brown planthopper, Nilaparvata lugens (Stal.) in rice. J. Appl. Zool. Res. 13(1): 14-18. Velusamy, R., Ganeshkumar, R. M. and Johnson, Y. S. 2006. Mechanisms of resistance to the brown planthopper Nilaparvata lugens in wild rice (Oryza spp.) cultivars. Entomol. Exp. Appl. 74(3): 245-251. Wu, J. T., Heinrichs, E. A. and Medrano, F. G. 1986. Resistance of wild rices Oryza spp. to the brown planthopper, Nilaparvata lugens (Homoptera: Delphacidae). Environ. Entomol. 15: 648-653. 609

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