Fatal Attraction: Ricinus communis Provides an Attractive but Risky Mating Site for Holotrichia parallela Beetles.[Pubmed: 30116996]

The castor bean, Ricinus communis L., is a non-host plant for the large black chafer, Holotrichia parallela Motschulsky (Coleoptera: Scarabaeidae). In laboratory bioassays we found that this plant was no less attractive than the main host plant (peanut, Arachis hypogaea) and three food plant species: velvetleaf (Abutilon theophrasti), the glossy privet (Ligustrum lucidum), and the Siberian elm (Ulmus pumila). In field trapping experiments a Soxhlet extract of castor bean leaves caught more beetles than the optimal sex lure blend [(R)-(-)-linalool and (L)-isoleucine methyl ester blended in a ratio of 1:4], compared at equal doses (500 μl), and laboratory bioassays indicated that a castor bean plant could enhance the attractiveness of different blend ratios of sex lures. Olfactometer bioassays showed that males prefer volatiles emitted from different combinations of castor bean plant extracts and a signaling female over a female alone. In the presence of castor bean plants copulation rates of H. parallela were highest among all test environments both in laboratory bioassays (60%) and in field tests (70%). This study, combined with our previous observation of the feeding behavior of H. parallela adults on castor bean leaves, suggests that castor bean plants may provide an attractive but risky mating site for H. parallela beetles. The enhancement of male mate-location and copulation rate in the presence of castor bean plants can balance its paralytic effects on H. parallela after intake of potential toxins contained in its leaves.

Effects of sublethal herbicides on offspring germination and seedling growth: Redroot pigweed (Amaranthus retroflexus) vs. velvetleaf (Abutilon theophrasti).[Pubmed: 30029130]

The effects of sublethal doses of herbicides on plants cannot be ignored, yet little is known about the effects of sublethal doses of herbicides on the F1 generation of plants. Seed germination and seedling growth of native and invasive plants following the sublethal exposure of parent plants to herbicides were comparatively analyzed in this study. Sublethal atrazine and tribenuron-methyl had carry-over effects on the germination and seedling growth of the F1 generation of invasive redroot pigweed (Amaranthus retroflexus L.) and native velvetleaf (Abutilon theophrasti Medicus), both of which had different responses to the carry-over effects of sublethal herbicide. The germination percentage of the F1 redroot pigweed (decreased) was greater than that of the F1 velvetleaf (increased or not significantly changed) following parental exposure to atrazine or tribenuron-methyl. Atrazine reduced the radical growth of 7-day-old velvetleaf seedlings and decreased the difference in seedling length between velvetleaf and redroot pigweed, while tribenuron-methyl had no significant effects on the growth of 7-day-old velvetleaf seedlings. The herbicide inhibition effect on the germination and growth of F1 velvetleaf and redroot pigweed did not increase as the sublethal dose increased. This study suggests that carry-over effects of sublethal herbicides weaken the growth advantage of the F1 velvetleaf at the seedling stage and may have a more negative influence on progeny population development of native velvetleaf compared with invasive redroot pigweed.

RESEARCH ON EXTRACTION TECHNOLOGY, ANTIBACTERIAL AND ANTIOXIDANT ACTIVITY OF ETHANOL EXTRACT FROM LEAVES OF ABUTILON THEOPHRASTI MEDIC.[Pubmed: 29513957]

This paper described the extraction procedure and determination method for the total flavonoids in ethanol extract from the leaves of Abutilon theophrasti Medic., and evaluated antibacterial and antioxidant activity. Maximum extraction yield was achieved using 60% ethanol, 1 : 30 (g/mL) of a ratio of material to solvent, 20 min of extraction time, 40 kHz of ultrasonic frequency, 100 W of ultrasonic power, 600C of extraction temperature and two extraction cycles. Total flavonoids content was 16.79 RE mg/g medicinal materials. The extracts had effective antibacterial activity against 24 test strains from S. aureus and E. coli, MICs ranged from 2.18 to 8.7 mg/mL; it was also revealed that the extracts demonstrated high flavonids content and potent antioxidant activity, achieved by hydroxyl radical, DPPH radical and ABTS radical scavenging. These results indicated thathe extract may be a promising plant demonstrating antibacterial and antioxidant activities.

Antibacterial and antioxidant properties of various solvents extracts of Abutilon theophrasti Medic. leaves.[Pubmed: 28653920]

This paper described the extraction procedure of six extracts from Abutilon theophrasti Medic. leaves and evaluated antioxidant and antibacterial activity of different extracts by hydroxyl radical, DPPH radical scavenging, broth micro-dilution and agar-well diffusion methods. The six extracts were prepared by the two extraction procedures: (I) water was the extraction solvent; (II) 90% alcohol extract was extracted by petroleum ether, chloroform, ethyl acetate and n-butanol in turn. Extract yields were 7.34%, 7.31%, 0.45%, 0.12%, 2.70% and 5.68% for extract I to VI. It was revealed that the various extracts had effective antibacterial activity against four test strains from Staphylococcus aureus (ATCC 25923), Streptococcus (ATCC 49619), Escherichia coli (ATCC 25922) and Salmonella (ATCC 01303); meanwhile, the six extracts demonstrated potent antioxidant activity, achieved by hydroxyl radical and DPPH radical scavenging assay. Minimum inhibitory concentrations (MICs) for the bacterial species ranged from 2.21 to 539.46 mg/ml, diameter of inhibition zone ranged from 2.08 to 15.05mm. The scavenging •OH and DPPH• rates were 62.37% to 81.86% with the concentration 0.06 to 1.89mg/ml and 37.80% to 81.23% with the concentration 1.07 to 35.52mg/ml. According to the results, these extracts have antioxidant and antibacterial activity. In view of all the facts collectively, the six extracts will become natural and nontoxic antioxidant and antibacterial agent, and be applied in food and pharmaceutical industries for the prevention or treatment caused by microorganisms and free radicals.