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In vitro biological activities including anti-phytopathogenic fungi, antibacterial, antifeedant and herbicidal activities of the extracts from the heartwoods of Mansonia gagei Drumm. were evaluated. The dichloromethane (DCM) extract displayed antifungal activity against four plant pathogenic fungi: Alternaria porri, Colletotrichum gloeosporioides, Fusarium oxysporum and Phytophthora parasitica higher than the methanolic (MeOH) extract. The separation of the DCM extract using bioassay guided antifungal activity against P. parasitica led to the isolation of mansorins A, B, and C, mansonones C, E, G and H. Among isolated compounds, mansonone E displayed the highest antifungal activity against P. parasitica, followed by mansonone C, mansorin B and mansonone G. This potent compound revealed the same minimum inhibitory concentrations (MIC) of 31 µg mL-1 against C. gloeosporioides and P. parasitica, and minimum fungicidal concentration (MFC) of 31 and 125 µg mL-1 , respectively. Moreover, mansonone E exhibited highly significant antibacterial activity against both Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc) with MIC and minimum bactericidal concentration (MBC) as 7.8 and >500 µg mL-1 , respectively. This compound furthermore could inhibit the feed of Spodoptera litura with 45.9% antifeedant and significantly herbicidal activity reduced the shoot and root growth of Brassica chinensis, Oryza sativa, Mimosa pigra and Echinochlooa crus-galli. Mansonone E has potential as a new natural pesticide for agricultural plant pathogen management.

In this study, genetic diversity and structure of 474 cultivated and 19 wild lablab (Lablab purpureus) accessions. were determined using 15 nuclear and 6 chloroplast SSR markers. The overall gene diversity was relatively low (0.3441). Gene diversity in the wild accessions (0.6059) was about two-folds greater than that in the cultivated accessions. In the wild accessions, gene diversity was greatest in the southern Africa, followed by East Africa. In the cultivated accessions, gene diversity was highest in the eastern Africa. The results suggested that South Africa is the center of origin and East Africa is the center of domestication of lablab. Different cluster analyses showed that 2-seeded-pod cultivated accessions (ssp. uncinatus) were clustered with wild accessions and that 4–(6)-seeded-pod cultivated accessions (ssp. purpureus and bengalensis) were intermingled. UPGMA tree suggested that ssp. purpureus and bengalensis were domesticated from 4-seeded-pod wild accessions of southern Africa. Haplotype network analysis based on nuclear SSRs revealed two domestication routes; the ssp. uncinatus is domesticated from 2-seeded-pod wild lablab (wild spp. uncinatus) from East Africa (Ethiopia), while the ssp. purpureus and bengalensis are domesticated from 4-seeded-pod wild lablab from Central Africa (Rwanda). These results are useful for understanding domestication and revising classification of lablab.

The management of weeds and diseases that are caused by phytopathogenic fungi is important for preventing the loss of agricultural products. The aim of the present study was to identify phytotoxic and antiphytopathogenic agents from the Thai Alpinia galanga rhizome. Extracts of the dried rhizomes of A. galanga (Zingiberaceae) were separated and tested for phytotoxic activity against lettuce (Lactuca sativa L. cv. Great Lakes) and Italian ryegrass (Lolium multiflorum Lam. cv. Wasefudou) and for antiphytopathogenic activity against Alternaria porri, Colletotrichum gloeosporioides, Fusarium oxysporum and Phytophthora nicotianae. 1′‐Acetoxychavicol acetate (1) was identified as one of the main components, together with trans‐p‐coumaryl acetate (3) and trans‐p‐acetoxycinnamyl acetate (2). 1′‐Acetoxychavicol acetate (1) was solvolyzed with 2% EtOH to yield trans‐p‐coumaryl ethyl ether (6), trans‐p‐coumaryl acetate (3) and trans‐p‐coumaryl alcohol (5). 1′‐Acetoxychavicol acetate (1) completely inhibited the root growth of the lettuce seedlings at 50 μg mL–1, but had a weaker inhibitory effect on the growth of Italian ryegrass. 1′‐Acetoxychavicol acetate also inhibited the growth of P. nicotianae and A. porri, with minimum inhibition concentration values of 15.6 and 31.5 μg mL–1, respectively. The plant growth‐inhibitory activity and fungal growth‐inhibitory activity of trans‐p‐coumaryl acetate (3), trans‐p‐coumaryl ethyl ether, trans‐p‐coumaryl alcohol (5) and trans‐p‐acetoxycinnamyl acetate (2) were lower than those of 1′‐acetoxychavicol acetate. A structure–activity relationship suggested that the strong phytotoxic and antiphytopathogenic activity of 1′‐acetoxychavicol acetate relied on the 1′‐acetoxyl group.