Yan-Chang Wang

Penetration into rice tissues by brown planthopper and fine structure of the salivary sheaths

The fine structure of the salivary sheaths in plant tissues can provide important information on homopteran probing and ingestion behaviors. Salivary sheaths secreted by the brown planthopper (BPH), Nilaparvata lugens (Stål) (Homoptera: Delphacidae), and their tissue pathway were investigated using light, scanning electron, and transmission electron microscopy. About half of the salivary flanges on the surface of the food substrate were connected with internal salivary sheaths. Only 43% of the salivary sheaths showed side branches. Many sculpture‐like protuberances and small cavities had been formed on the outer surface of the salivary sheath, but the sheath lumen circumferences were sealed. Brown planthoppers showed a preference for probing and leaving salivary sheaths in the susceptible rice variety TN1 rather than in the resistant variety B5 during the first 2 days of the experiments. The salivary sheaths in rice tissues reached the inner tissue layer of the leaf sheaths and stems, but were mostly observed to end in the first and second layer of the leaf sheaths. Brown planthoppers also preferred to probe into the thick segment of the outer leaf sheath. After ingestion by the insect, the cytoplasm in both phloem and companion cells degraded and the main organelles were lost. Numerous small vesicles were found in most of the phloem cells, but cell walls remained intact. Large numbers of symbiont‐like structures were observed inside the salivary sheath lumen. These results indicated that BPH has complicated feeding behaviors, which warrants further investigation.

Development of microsatellite markers in Actinidia arguta (Actinidiaceae) based on the NCBI data platform

PREMISE OF THE STUDY Expressed sequence tag (EST)-derived microsatellite markers in Actinidia arguta were developed for genotyping and genetic mapping. METHODS AND RESULTS One hundred and fifty EST-simple sequence repeat (SSR) primer pairs were obtained from the National Center for Biotechnology Information (NCBI) A. chinensis database using SSR Hunter 1.3. With the other 20 reported primers, 170 primer pairs were screened using 16 samples. A total of 72 primers pairs were successively developed for A. arguta. Fifteen of the developed markers were characterized in A. arguta populations from Changbai Mountain and Daba Mountain. The mean number of alleles per locus in the Changbai and Daba populations was 5.133 and 4.133, respectively. CONCLUSIONS Development of Actinidia ESTs from the NCBI database is an effective method of obtaining SSR markers for A. arguta. These markers will be useful for genome mapping and molecular breeding in A. arguta.