Photosynthesis and Translocation of Assimilates in Rice Plants Following Phloem Feeding by the Planthopper <I>Nilaparvata lugens</I> (Homoptera: Delphacidae)

Abstract

Experiments were conducted to measure the effect of feeding by the planthopper Nilaparvata lugens (Stål) on photosynthesis and the translocation of assimilates in rice plants, Oryza sativa L. We used mature japonica rice plants and applied the 13CO2 feeding method to evaluate those physiological effects. The photosynthetic rate was suppressed by N. lugens infestation, especially at the lower leaf position, with rates 30% lower than that of control plants at the booting stage. Leaf nitrogen concentration in infested plants was also lower than that in control plants. After flowering, the chlorophyll content and total plant dry weight were reduced by N. lugens. Stem and sheath dry weights were significantly reduced by N. lugens infestation, whereas panicle dry weight was not affected. Little effect was found on disruption in translocation of assimilates, even when 13CO2 was supplied to the infested leaves. Results suggested that removal of assimilates and reduction in photosynthesis by N. lugens have the greatest effect on growth and yield of rice plants as compared with the disruption in the translocation of assimilates. Plant death can occur by N. lugens infestation if the amount of energy supplied is less than that required for tissue maintenance.

Exogenous Application of Jasmonic Acid Induces Volatile Emissions in Rice and Enhances Parasitism of Nilaparvata lugens Eggs by theParasitoid Anagrus nilaparvatae

“…N. lugens is one of the most important rice pests. It feeds on the plant's phloem and causes a decrease in leaf area, plant height, dry weight, leaf and stem nitrogen concentration, chlorophyll contents, and photosynthetic rate, but an increase in free amino acids, sucrose, and leaf iron content (Rubia-Sanchez et al, 1999;Watanabe and Kitagawa, 2000). The parasitoid A. nilaparvatae is a major natural enemy of the rice planthoppers.…”

Differences in Induced Volatile Emissions among Rice Varieties Result in Differential Attraction and Parasitism of Nilaparvata lugens Eggs by the Parasitoid Anagrus nilaparvatae in the Field

“…It feeds on the phloem and causes a decrease in leaf area, plant height, dry weight, leaf and stem nitrogen concentration, chlorophyll contents, and photosynthetic rate (Rubia-Sanchez et al, 1999;Watanabe and Kitagawa, 2000), which subsequently results in yield loss. Previous studies have shown that N. lugens attack or JA treatment alters the volatile profiles of rice plants, and these volatiles are strongly attractive to the egg parasitoid Anagrus nilaparvatae (Lou et al, 2005a,b), a major natural enemy of the rice planthoppers (Cheng and He, 1996).…”

Identification and characterization of genomic regions associated with nitrogen dynamics in rice plants (Oryza sativa L.)

“…For rice, leaves of the lower position act as major source organs for the carbohydrates and nitrogen used in roots and panicles, respectively, during maturity (Sawada et al 1995, Watanabe and Kitagawa 2000, Yamada et al 2002. Despite their physiological importance, few genetic studies have been conducted to analyze N concentrations in the lower leaves.…”