This work suggested that L. nobilis oil could be used as a potential fungicide to control the post-harvest disease caused by A. alternata.

Background Monochasma savatieri is an endangered hemiparasitic medicinal plant with a variety of antioxidant, antimicrobial and anti-inflammatory properties. Despite the urgent need to understand the parasitic biology of M. savatieri, parasite-host associations have long been neglected in studies of M. savatieri. Methods We conducted a pot cultivation experiment to analyze changes in the growth traits, physiological performance and anatomical structures of M. savatieri grown with the potential host Gardenia jasminoides E., before and after the establishment of the parasite-host association. Results Prior to the establishment of the parasite-host association, the presence of the host had no significant effect on the maximum root length, leaf indexes or total dry weight of M. savatieri seedlings, but had significant positive effect on seedling height, number of roots or number of haustoria. When it was continuously grown without a host, M. savatieri growth was rather slow. The establishment of the parasite-host association enhanced the growth of M. savatieri, and higher levels of photosynthetic pigments, increased antioxidant enzyme activity and lower malondialdehyde accumulation were observed in M. savatieri with an established parasite-host association. Furthermore, an analysis of the anatomical structures of M. savatieri showed that the establishment of the parasite-host association enabled better development of the seedling vegetative organs than that in seedlings without parasite-host associations. Conclusions Our study demonstrates the physiological and anatomical changes that occurred in M. savatieri after connection with a host and suggests that the enhanced growth and development of M. savatieri were highly dependent on the parasite-host association.

Volatiles emitted by healthy, mechanically damaged, and weevil-infested Artemisia ordosica (Asteraceae) were obtained through a dynamic headspace method and analysed by automatic thermal desorption/gas chromatography/mass spectrometry (ATD/GC/MS). Twenty-eight compounds in all were identified, and the qualitative as well as quantitative differences were compared. The green leaf volatiles 2-hexenal, (Z)-3-hexen-1-ol, 2-hexen-1-ol, 1-hexanol, and (Z)-3-hexen-1-ol acetate were present in all of the damaged plants, but in relatively lower portions when plants were infested by the weevil Adosopius sp., while the terpenoids alpha-copaene, beta-cedrene, and (E,E)-alpha-farnesene and the ester methyl salicylate were only present in weevil-damaged plants. The volatiles from healthy and weevil-infested leaves were dominated by D-limonene, whereas mechanically damaged leaves emitted beta-pinene as the dominant compound.

The small seeds of loquat possess very rich and diverse genetic characteristics which can potentially serve as precious resources for plant breeding. However, they are often aborted during the seed development. Cytokinin, as an important signaling mediator, plays a pivotal regulatory role in seed development. However, the effects of exogenous cytokinin application on the development of loquat seeds are poorly understood. In this study, we analyzed the potential effects of exogenous cytokinin on the abortion of small seeds of loquat. Cytokinin (20 mg/L trans-zeatin) and cytokinin inhibitor (60 mg/L lovastatin) were sprayed on the fruits of ‘Dawuxing’ loquat during an early stage of fruit expansion. The clean water treatment was used as the control group. The results showed that exogenous trans-zeatin significantly increased the weight of small seeds, the levels of soluble sugar and starch, as well as peroxidase (POD) and superoxide dismutase (SOD) activities. It also promoted a substantial increase in the expression of POD- and SOD-related genes during the process of small seed abortion. Moreover, trans-zeatin treatment significantly increased the content of endogenous trans-zeatin in the small seeds, and this increase in content showed a trend opposite to that of control (CKA). Cytokinin dehydrogenase related genes were found to be down-regulated after trans-zeatin treatment. It was found that exogenous cytokinin inhibitor (lovastatin) treatment could induce the anti-stress reaction in the small seeds during the early stage of treatment by significantly increasing the activities of POD and SOD, and the weight of small seeds at the early stage of treatment was significantly lower than that of the control group, but reverted to the level of the control group during the late stage of the treatment. Therefore, a specific concentration of trans-zeatin treatment can promote the development of small loquat seeds, while cytokinin inhibitor (lovastatin) can significantly inhibit the development of small seeds during the early stage of treatment. In summary, this study reports for the first time that application of exogenous trans-zeatin could effectively promote the development of small loquat seeds by significantly increasing the metabolism of small seeds. The small seeds which contained rich and diverse genetic characteristics often aborted during seed development. Our study thus established a foundation for the rescue of new germplasm resources of loquat by promoting the development of small loquat seeds.

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