Effect of Elevated CO 2 on Biology of Brown Planthopper, Nilaparvata - PowerPoint PPT Presentation

Effect of Elevated CO 2 on Biology of Brown Planthopper, Nilaparvata lugens Presented by K.Chiranjeevi Senior Research fellow Indian Institute of Rice Research, Rajendranagar,Hyderabad

Introduction Global average temperature increased by 0.6 o C in 20 th century while CO 2 reached  upto 380ppm till date. By the end of 21 st century the global average temperature is projected to increase by 1.4-7.5 o C and CO 2 level to 560ppm, if the anthropogenic activities continue at the same speed (IPCC, 2007).  Brown Planthopper (BPH), Nilaparvata lugens Stal, is one such pest in rice known for its seasonal migration and r strategy pattern of life. Eggs Hopper burn caused by BPH Nymphs Adults BPH Life cycle  Both nymphs and adults of the hopper suck the sap from phloem resulting in wilting and drying up of the rice plant and known as “Hopper burn”  Adults- Long winged Macroptery and short winged Brachypterous form  It also acts as the vector of Rice Grassy Stunt (Rivera et al. 1966) and Ragged Stunt Viruses (Ling et al. 1978).

Objectives 1. Effect of temperature and elevated CO 2 on the biology of BPH viz., development, longevity and fecundity in 5 th and 13 th generations. generations. 2. Feeding Behavior

Materials and Methods  Three BPH populations- West Godavari, Punjab and Nalgonda  Japanese method of rearing was followed for mass rearing  Effect of elevated CO 2 on Biology, feeding rate was assessed   CO2 treatments: BPH populations rearing on flexi glass cages 1.Elevated CO 2 @550ppm with temperature control(28.0 ± 0.3) 0 C,RH(70 ± 5%) 2. Elevated CO @550ppm without temperature 2. Elevated CO 2 @550ppm without temperature control(31.0 ± 0.3) 0 C,RH(63 ± 5%) 3. Ambient CO 2 @380ppm and temperature (28.0 ± 0.3) 0 C,RH(70 ± 5%) biology study  biology of BPH was studied in 5 and 13 th generations. One 1 st instar nymph was released in each test tube (25x200cm) on 15 days old TN1 plant and added with Hoagland solution. 40 replications were used  Feeding was measured as amount of honeydew secreted by five 3 rd instar nymphs during 24h of feeding on TN1 Honeydew experiment set up

Results: Elevated CO 2 vs. Biology of BPH Nymphal Duration (13 th gen) Nymphal duration (5 th gen) 18 17.5 16 Nymphal duration(days) 17 Nymphal duration (days) 14 16.5 16 12 WG 15.5 WG 10 PNJ 15 PNJ 8 NLG 14.5 NLG 6 14 4 13.5 2 13 0 12.5 eco2+aT eco2+eT aco2+aT eCO2+aT eCO2+eT aCO2+aT 5 th generation: Prolonged nymphal duration was observed at eCO 2 +aT compare to eCO 2 +eT and aCO 2 + aT in Punjab and Nalgonda BPH whereas in West Godavari BPH, nymphal duration had not shown significant difference between three CO 2 levels. 13 th generation: Prolonged nymphal duration was observed at eCO 2 +aT compare to eCO 2 + eT and aCO 2 + aT in all BPH populations, Nymphal duration of West Godavari, Punjab and Nalgonda BPH at eCO 2 +aT was 15.9 ±0.2, 16.2±0.2, 16.1±0.2 days respectively

Elevated CO2 vs Female longevity (5 th gen.) Punjab BPH- 5th gen. West Godavari BPH- 5th gen. 14 7.4 12 7.2 10 7 longevity (days) 6.8 longevity (days) 8 6.6 6 6.4 female longevity 6.2 female 4 6 longevity 2 5.8 5.6 0 eco2+aT eco2+eT aco2+aT eco2+aT eco2+aT eco2+eT eco2+eT aco2+aT aco2+aT Nalgonda BPH- 5th gen. West Godavari BPH - Female longevity 12 had not shown significant difference at 10 longevity (days) elevated co2 levels 8 6 4 Higher longevity noticed at eCO2+aT female longevity 2 In Punjab & Nalgonda populations 0 eco2+aT eco2+eT aco2+aT

Elevated CO2 vs Male longevity (5 th gen.) Punjab BPH- 5th gen. West Godavari BPH- 5th gen. 14 10 12 10 longevity(days) longevity (days) 9 8 6 male male longevity 8 4 longevity 2 7 0 eco2+aT eco2+eT aco2+aT eco2+aT eco2+eT aco2+aT Nalgonda BPH- 5th gen. 14 Longevity of males in West Godavari BPH had 12 5 th gen. not shown much difference at three CO 2 levels longevity(days) 10 Longevity of males reduced at aCO2+aT in whereas, in Punajb BPH it was observed that 8 West Godavari & Nalgonda BPH males were survived more at eCO 2 + eT 6 male (12.5±1.6 d) while in Nalgonda BPH longevity 4 Punjab BPH it was observed that males were 2 survived more at eCO 2 + eT (12.5±1.6 d) 0 eco2+aT eco2+eT aco2+aT

Elevated CO2 vs Female longevity (13 th gen.) 25 Punjab BPH-13th gen. West Godavari BPH-13th gen. 18 20 female longevity (days) 16 14 Female longevity (days) 15 12 10 10 8 female 6 female longevity 4 longevity 5 2 0 0 eco2+aT eco2+eT aco2+aT eco2+aT eco2+eT aco2+aT Nalgonda BPH-13th gen. 13 th gen 15 Longevity of females were higher at eCO2+aT female longevity (days) in three BPH populations. West 10 Godavari, Punjab & Nalgonda female longevity 5 0 eco2+aT eco2+eT aco2+aT

Elevated CO2 vs Male longevity (13 th gen.) West Godavari BPH-13th gen. Punjab BPH-13th gen. 14 10 12 9.8 Male longevity (days) 10 Male longevity (days) 9.6 8 9.4 6 male male 9.2 longevity longevity 4 9 2 8.8 0 eco2+aT eco2+eT aco2+aT eco2+aT eco2+aT eco2+eT eco2+eT aco2+aT aco2+aT 13 th gen Nalgonda BPH-13th gen. 11.5 Longevity of males were higher at Male longevity (days) 11 eCO2+eT in West Godavari but its 10.5 decreased in Punjab bph whereas in 10 male Nalgonda had not affects by eCO2 levels. longevity 9.5 9 eco2+aT eco2+eT aco2+aT

Fecundity of BPH populations at three different CO2 levels West Godavari BPH-5 th gen. Punjab BPH-5 th gen. 90 140 80 120 No of eggs laid by by female 70 100 60 80 50 fecundity fecundity 60 40 40 30 20 20 10 0 0 eco2+aT eco2+eT aco2+aT eco2+aT eco2+eT aco2+aT Nalgonda BPH-5 th gen. 5 th gen 120 No of eggs laid by by female 100 80 Fecundity was higher at eCO2+eT in 60 fecundity Nalgonda BPH. 40 20 West Godavari & Punjab bph had not 0 affects by eCO2 levels. eco2+aT eco2+eT aco2+aT

Fecundity of BPH populations at three different CO2 levels in 13 th generation Punjab BPH-13 th gen. West Godavari BPH-13 th gen. 350 350 No of eggs laid by female No of eggs laid by female 300 300 250 250 200 200 fecundity 150 fecundity 150 100 100 50 50 0 eco2+aT eco2+eT aco2+aT 0 eco2+aT eco2+eT aco2+aT Nalgonda BPH-13 th gen. 13 th gen 300 No of eggs laid by female 250 Fecundity was higher at eCO2+eT in 200 West Godavari BPH whereas Punjab bph 150 fecundity 100 showing lower fecundity at eCO2+eT 50 0 Nalgonda not affects by eCO2 levels. eco2+aT eco2+eT aco2+aT

Feeding rate of three BPH populations at different CO2 levels(5 th gen.) West Godavari BPH-5th gen. Punjab BPH-5th gen. 140 90 honeydew excretion by 3rd instar honeydew excretion by 3rd instar 120 80 70 100 60 nymphs(mm 2 ) nymphs(mm 2 ) 80 50 feeding 40 60 rate feeding 30 40 rate 20 20 10 0 0 eco2+aT eco2+eT aco2+aT eco2+aT eco2+eT aco2+aT 5 th gen Nalgonda BPH-5th gen. 120 Honeydew excretion was not significantly 3rd instar nymphs (mm 2 ) 100 honeydew excretion by affected by elevated CO2 levels in West 80 Godavari & Punjab bph. 60 feeding 40 rate 20 Feeding rate was higher at eCO2+eT- 0 Nalgonda eco2+aT eco2+eT aco2+aT 13 th generation- data to be analysed.

Effect of elevated CO 2 levels on biochemical composition of rice plants (infested and uninfested bph) Biochemical analysis Indirect effect of elevated CO2 and temperature on bph infested and uninfested TN1 plants at different growth stages (30 and 60 days) is under being progress.  Proteins estimation by- Lowry et al.,(1951)    Total Phenols- Swain and Hillis (1959)  Total Sugars- Yoshida et al., (1976)   Reducing sugars- Nelson,(1944)  Reducing sugars- Nelson,(1944)  Non-reducing sugars- Loomis and Shull, (1937)    NPK

Conclusion and future prospects 1. The results revealed that effects of elevated CO 2 and ambient temperature was increases the developmental duration, longevity and fecundity of BPH. Higher feeding rate was observed only in Nalgonda population at elevated CO 2 with increasing temperature , highly feeding may be due to enzymes are play key role (plants & insects) will be analyzed. 2. This results clearly indicates that insects from tropical and temperate regions exposed to different temperature regimes will show varied responses to climate change factors. 3. Screening of CO 2 adapted populations along in comparison with normal population for identified resistant genotypes/varieties by special screening techniques will help us to understand the mechanisms of population adaptation to host plant resistance under climate change. Acknowledgement This work has been carried out under NICRA project and we thank the Project Director, IIRR for the facilities