Kajian anatomi dan mikromorfologi daun telah dijalankan ke atas lima takson dalam genus Schoutenia Korth. (Malvaceae subfam. Brownlowioideae). Lima takson yang dipilih dalam kajian ini ialah S. kunstleri, S. leprosula, S. accrescens subsp. accrescens, S. accrescens subsp. borneensis dan S. accrescens subsp. stellata. Kajian anatomi melibatkan kaedah hirisan dengan mikrotom gelongsor pada bahagian petiol, lamina, tulang daun dan tepi daun, kaedah penjernihan lamina dan kaedah siatan epidermis daun, penjernihan dengan larutan peluntur, pewarnaan dengan Safranin dan Alcian Blue, pelekapan Canada Balsam dan cerapan bawah mikroskop cahaya. Kajian mikromorfologi melibatkan kaedah pendehidratan, titik pengeringan kritikal, saduran emas dan cerapan bawah mikroskop imbasan elektron. Objektif kajian ialah untuk melihat nilai taksonomi ciri anatomi dan mikromorfologi daun dalam genus yang dikaji. Hasil kajian menunjukkan terdapat sembilan ciri sepunya, tujuh ciri variasi yang boleh digunakan untuk pembezaan spesies dan dua ciri diagnostik yang boleh digunakan untuk pengecaman spesies. Ciri tersebut ialah corak hiasan kutikel pada S. kunstleri dan juga kehadiran sel kolenkima lamela pada S. accrescens subsp. stellata. Hasil kajian menunjukkan ciri anatomi serta mikromorfologi daun dalam genus Schoutenia mempunyai nilai taksonomi terutama dalam pembezaan dan pengecaman pada peringkat spesies dan subspesies.
Clausena lansium, also known as wampee (Clausena wampi), is a plant species native to China, Vietnam, the Philippines, Malaysia, and Indonesia, where it is widely cultivated, and also grown in India, Sri Lanka, Queensland, Florida, and Hawaii, but less frequently (3). The fruit can be consumed fresh or made into juice, jam, or succade. In summer to fall 2014, a soft rot disease was found in a wampee planting region in Yunan County, Guangdong Province, China. On Sept. 18, we collected diseased samples from a wampee orchard with about 20% disease incidence. The infected fruit initially showed pinpoint spots on the peel, water-soaked lesions, and light to dark brown discoloration. Spots expanded in 2 days, and tissues collapsed after 5 days. Severely affected fruit showed cracking or nonodorous decay. Five diseased samples were collected, and causal agents were isolated from symptomatic tissues 1 cm under the peel after surface sterilization in 0.3% NaOCl for 10 min and rinsing in sterile water three times. Tissues were placed on a Luria Bertani (LB) plate for culture. Ten representative isolates were selected for further characterization. No colony was isolated from healthy tissues. Colonies were round, smooth, with irregular edges, and produced a yellow pigment in culture. Biolog identification (Version 4.20.05) showed that all strains were gram negative, negative for indole production, and utilized glucose, maltose, trehalose, sucrose, D-lactose, and pectin but not sorbitol or gelatin. The isolates were identified as Pantoea agglomerans (SIM 0.69). Multilocus sequence analysis (MLSA) was conducted for rapid classification of the strains. Sequences of atpD, gyrB, infB, and rpoB were amplified using corresponding primers (2). All sequences of the 10 isolates were identical in each gene. BLASTn was performed, and maximum likelihood trees based on the concatenated nucleotide sequences of the four genes were constructed using MEGA6. Bootstrap values after 1,000 replicates were expressed as percentages. Results showed that the tested strain named CL1 was most homologous to P. anthophila, with 98% identity for atpD (KM521543), 100% for gyrB (KM521544), infB (KM521545), and rpoB (KM521546). The 16S rRNA sequence (KM521542) amplified by primers 27f and 1492r shared 99% identity with that of P. anthophila M19_2C (JN644500). P. anthophila was previously reclassified from P. agglomerans (3); therefore, we suggest naming this wampee pathogen P. anthophila. Subsequently, 10 wampee fruits were injected with 20 μl of bacterial suspension (1 × 108 CFU/ml) of strains CL1 and CL2, respectively, and another 10 were injected with 20 μl of LB medium as controls, all kept at 28°C for 4 days. Symptoms similar to those of natural infections were observed on inoculated fruits but not on the negative controls. Bacteria were isolated from diseased tissues and further identified as P. anthophila by gyrB sequencing. P. anthophila was reported to naturally infect balsam and marigold (1,2). To our knowledge, this is the first report of P. anthophila naturally causing soft rot disease and cracking on C. lansium (wampee). References: (1) C. Brady et al. Syst. Appl. Microbiol. 31:447, 2008. (2) C. Brady et al. Int. J. Syst. Evol. Microbiol. 59:2339, 2009. (3) J. Morton. Fruits of Warm Climates. Echo Point Books & Media, Miami, FL, 1987.