Dynamics of Yeast-like Symbiote and its Relationship with the Virulence of Brown Planthopper, Nilaparvata lugens Stal, to Resistant Rice Varieties

Zhong-Xian Lu,Xiao-Ping Yu,Jian-Ming Chen,Xu-Song Zheng,Hong-Xing Xu,Jue-Feng Zhang Zhang,Lie-Zhong Chen 한국응용곤충학회 2004 Journal of Asia-Pacific Entomology Vol.7 No.3

Abundance of the yeast-like symbiote (YLS) in brown planthopper (BPH), Nilaparvata lugens Stl, collected from rice fields in China and obtained from International Rice Research Institute (IRRI), was monitored. The role of YLS in nymph survival rate, development and adult reproduction, and activities of transaminases in BPH on different resistant rice varieties were examined. Also, the relationship between YLS and virulence shifts of BPH to resistant rice varieties was discussed. The results indicated that the virulence of BPH populations to resistant rice varieties was strongly related to the abundance of YLS in 5th instar nymphs and brachypterous females of BPH field populations at Nanning in South China and Hangzhou in East China, showing the more abundance of YLS in BPH, the higher virulence of BPH to resistant rice varieties, while no obvious differences in YLS abundance were monitored between three BPH biotypes. Numbers of YLS reduced significantly in female adult of BPH biotype 1 fed on resistant rice varieties IR26, Mudgo and ASD7, compared with that fed on susceptible rice variety TN1. The lowest YLS abundance of BPH from field population was found in 2nd generation successively fed on resistant varieties, and the number of YLS was resumed at 4th generation when the BPH has adapted the resistant varieties. The markedly lower nymphal survival rate, adult fecundity and activities of alanine and aspartic transminase, and significantly longer nymph duration in the three aposymbiotic biotypes than in the symbiotic ones were recorded on both susceptible and resistant rice varieties. However, the much greater differences between aposymbiotic and symbiotic BPH were found on the inadaptable resistant rice varieties than that on the fitness resistant rice varieties. Those results implied that YLS in BPH should play a crucial role in the virulent shift of BPH populations to resistant rice varieties.

Dynamics of Yeast-like Symbiote and Its Relationship with the Virulence of Brown Planthopper, Nilaparvata lugens Stal, to Resistant Rice Varieties

Lu, Zhong-Xian,Yu, Xiao-Ping,Chen, Jian-Ming,Zheng, Xu-Song,Xu, Hong-Xing,Zhang, Jue-Feng,Chen, Lie-Zhong Korean Society of Applied Entomology 2004 Journal of Asia-Pacific Entomology Vol.7 No.3

Abundance of the yeast-like symbiote (YLS) in brown planthopper (BPH), Nilaparvata lugens Stal, collected from rice fields in China and obtained from International Rice Research Institute (IRRI), was monitored. The role of YLS in nymph survival rate, development and adult reproduction, and activities of transaminases in BPH on different resistant rice varieties were examined. Also, the relationship between YLS and virulence shifts of BPH to resistant rice varieties was discussed. The results indicated that the virulence of BPH populations to resistant rice varieties was strongly related to the abundance of YLS in 5th instar nymphs and brachypterous females of BPH field populations at Nanning in South China and Hangzhou m East China, showing the more abundance of YLS in BPH, the higher virulence of BPH to resistant rice varieties, while no obvious differences in YLS abundance were monitored between three BPH biotypes. Numbers of YLS reduced significantly in female adult of BPH biotype 1 fed on resistant rice varieties IR26, Mudgo and ASD7, compared with that fed on susceptible rice variety TN1. The lowest YLS abundance of BPH from field population was found in 2nd generation successively fed on resistant varieties, and the number of YLS was resumed at 4th generation when the BPH has adapted the resistant varieties. The markedly lower nymphal survival rate, adult fecundity and activities of alanine and aspartic transminase, and significantly longer nymph duration in the three aposymbiotic biotypes than in the symbiotic ones were recorded on both susceptible and resistant rice varieties. However, the much greater differences between aposymbiotic and symbiotic BPH were found on the inadaptable resistant rice varieties than that on the fitness resistant rice varieties. Those results implied that YLS in BPH should playa crucial role in the virulent shift of BPH populations to resistant rice varieties.

The properties of hydrophobic concrete prepared by biomimetic mineralization method

Chung-Ho Huang,Hao-Yu Fang,Jue-Zhong Zhang 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.23 No.5

In this study, the calcium hydroxide, an inherent product of cement hydration, was treated using biomimetic carbonation method of incorporating stearic acid to generate the hydrophobic calcium carbonate on concrete surface. Carbonation reaction was carried out at various CO2 pressure and temperatures and utilizing the Scanning Electron Microscope (SEM), chloride-ion penetration test apparatus, and compression test machine to investigate the hydrophobicity, durability, and mechanical properties of the synthesized products. Experimental results indicate that the calcium stearate may change the surface property of concrete from hydrophilicity to hydrophobicity. Increasing reaction temperature can change the particles from irregular shapes to needle-rod structures with increased shear stress and thus favorable to hydrophobicity and microhardness. The contact angle against water for the concrete surface was found to increase with increasing CO2 pressure and temperature, and reached to an optimum value at around 90°C. The maximum static water contact angle of 128.7 degree was obtained at the CO2 pressure of 2 atm and temperature of 90°C . It was also found that biomimetic carbonation increased the permeability, acid resistance and chloride-ion permeability of the concrete material. These unique results demonstrate that the needle-rod structures of CaCO3 synthetized on concrete surface could enhance hydrophobicity, durability, and mechanical properties of concrete.

Effects of SRBSDV-infected rice plants on the fitness of vector and non-vector rice planthoppers

Hong-Xing Xu,Hong-Xing Xu,Xu-Song Zheng,Yajun Yang,Jue-Feng Zhang Zhang,Zhong-Xian Lu 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.3

Southern rice black-streaked dwarf virus (SRBSDV) is a new member of the genus Fijivirus and transmitted by whitebacked planthopper (WBPH), Sogatella furcifera (Horváth). The rice area affected by SRBSDV and the subsequent damages are increasing rapidly. In current study, we evaluated the effects of SRBSDV-infected plants on the ecological fitness and the tolerance to adverse environmental factors of vector WBPH and non-vector brown planthopper (BPH), Nilaparvata lugens (Stål). Our study revealed that the fitness of WBPH and BPH were both influenced by feeding on SRBSDV-infected rice. Fecundity ofWBPH feeding on the SRBSDV-infected rice plants were higher than those on healthy plants, nymphal duration of male WBPH prolonged markedly by 0.77 d (P b 0.05), while the weight of brachypterous female adults significantly decreased (P b 0.05), and the average survival time shortened both at 26 °C and 31 °C, respectively. Median lethal time of WBPH on SRBSDV-infected and healthy rice plants were 80 h and 112 h at 26 °C, 64 h and 88 h at 31 °C, respectively. As for non-vector BPH, nymph survival rate decreased significantly by 11.22% (P b 0.05) and the longevity of female adults also shortened (P b 0.05), while hatchability of BPH eggs increased (P b 0.05). Survival time of BPH feeding on healthy rice at 26 °Cwas significant longer than those feeding on healthy and infected rice at 31 °C. The above results imply that the vectorWBPH suffers much stronger effects than non-vector BPH fromfeeding on SRBSDVinfected rice plants.

Optimization of the microemulsion formulation of curcuma oil and evaluation of its acaricidal efficacy against Tetranychus cinnabarinus (Boisduval) (Acari: Tetranychidae)

Cheng Zuo-Hui,Fan Fang-Fang,Zhao Jin-Zhong,Li Rui,Li Sheng-Cai,Zhang En-Jia,Liu Yu-Kun,Wang Jue-Ying,Zhu Xiang-Run,Tian Yong-Ming 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.4

The microemulsion formulation (hereafter formulation) of curcuma oil and its acaricidal efficacy against Tetranychus cinnabarinus Boisduval (Acari: Tetranychidae) were optimized in the laboratory to evaluate their spray effectiveness of oviposition inhibition and repellence. Ethovision XT6 was used to analyse the effects of the sublethal concentrations (LC 20 ) of curcuma oil and the formulation on the behaviors of T. cinnabarinus. The results showed that Tween-80 was the best surfactant, Isopropanol was the best co-surfactant and K m = 2:1 was the best condition for the formulation. The prepared microemulsions are stable under conditions of centrifugation and incubation for extended periods. The results showed that the effect of the spray bioassays of the formulation against T. cinnabarinus continuously increased during the experiment, but for curcuma oil almost no longer increase observed when the exposure time went beyond 24 h. Moreover, compared with curcuma oil (LC 50 = 0.716%), the spray bioassay of the formulation (LC 50 = 0.035%) was stronger against T. cinnabarinus. The repellency of the formulation to T. cinnabarinus was stronger with increasing exposure time, but that of curcuma oil declined after 12 h of exposure. The mobile distance of T. cinnabarinus treated with the formulation continuously declined during the experiment but that due to the curcuma oil almost no longer declined when the treatment time reached 12 h. The maximum mobile frequency of T. cinnabarinus treated by curcuma oil and the formulation was recorded at 6 h and 12 h, respectively. Thus, the formulation is a promising candidate as a botanical acaricide of green vegetables.