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Wampee (Clausena lansium) is an important evergreen fruit tree native to southern China that has a long history of use for medicinal purposes. Here, a chromosome-level genome of C. lansium was constructed with a genome size of 282.9 Mb and scaffold N50 of 30.75 Mb. The assembled genome contains 48.70% repetitive elements and 24,381 protein-coding genes. Comparative genomic analysis showed that C. lansium diverged from Aurantioideae 15.91–24.95 million years ago. Additionally, some expansive and specific gene families related to methyltransferase activity and S-adenosylmethionine-dependent methyltransferase activity were also identified. Further analysis indicated that N-methyltransferase (NMT) is mainly involved in alkaloid biosynthesis and O-methyltransferase (OMT) participates in the regulation of coumarin accumulation in wampee. This suggested that wampee's richness in alkaloids and coumarins might be due to the gene expansions of NMT and OMT. The tandem repeat event was one of the major reasons for the NMT expansion. Hence, the reference genome of C. lansium will facilitate the identification of some useful medicinal compounds from wampee resources and reveal their biosynthetic pathways.

Accurately detecting the anthocyanin content in eggplant peel is essential for effective eggplant breeding. The present study aims to present a method that combines hyperspectral imaging with advanced computational analysis to rapidly, non-destructively, and precisely measure anthocyanin content in eggplant fruit. For this purpose, hyperspectral images of the fruits of 20 varieties with diverse colors were collected, and the content of the anthocyanin were detected using high performance liquid chromatography (HPLC) methods. In order to minimize background noise in the hyperspectral images, five preprocessing algorithms were utilized on average reflectance spectra: standard normalized variate (SNV), autoscales (AUT), normalization (NOR), Savitzky–Golay convolutional smoothing (SG), and mean centering (MC). Additionally, the competitive adaptive reweighted sampling (CARS) method was employed to reduce the dimensionality of the high-dimensional hyperspectral data. In order to predict the cyanidin, petunidin, delphinidin, and total anthocyanin content of eggplant fruit, two models were constructed: partial least squares regression (PLSR) and least squares support vector machine (LS-SVM). The HPLC results showed that eggplant peel primarily contains three types of anthocyanins. Furthermore, there were significant differences in the average reflectance rates between 400–750 nm wavelength ranges for different colors of eggplant peel. The prediction model results indicated that the model based on NOR CARS LS-SVM achieved the best performance, with a squared coefficient of determination (R2) greater than 0.98, RMSEP and RMSEC less than 0.03 for cyanidin, petunidin, delphinidin, and total anthocyanin predication. These results suggest that hyperspectral imaging is a rapid and non-destructive technique for assessing the anthocyanin content of eggplant peel. This approach holds promise for facilitating the more effective eggplant breeding.

With the aim of improving the rapidity and accuracy of quadrotor UAV positional trajectory tracking, this paper proposes a fuzzy automatic disturbance rejection control of quadrotor UAV based on improved whale optimization algorithm (IWOA-Fuzzy-ADRC). (1) To address the problems of low accuracy and slow convergence of the traditional whale algorithm, a combination of logistic chaos mapping and skew tent mapping is applied to improve the diversity of the initial population. (2) The global search capability is strengthened to avoid falling into local optimum through introducing the cross operator and Gaussian variational operators. (3) The IWOA is employed to iteratively optimize the adjustment coefficients of the fuzzy active disturbance rejection controller, the calculus gain of the nonlinear state error feedback control (NLSEF), and the error correction coefficients of the expansive state observer (ESO). The simulation results demonstrate that compared with the traditional ADRC controller and PID controller, the proposed IWOA-Fuzzy-ADRC controller can effectively improve the control performance of the system, accurately track the desired flight trajectory, accelerate the dynamic response of the control system, reduce the steady-state error, and enhance the anti-interference capability.

Soil respiration is an important index to reflect soil quality and nutritional properties. However, these characteristics of latosol orchards of guava (Psidium guajava L. Pearl) in the south subtropics are not fully understood. In the present research, the effects of Stylo grass [Stylosanthes guianensis (Aubl.) Sw.] on soil respiration in guava orchards of latosol were studied. There were four treatments, namely, clean tillage, natural grass growth, Stylo grass 'Ubon' and 'Reyan No. 2'. Soil respiration was monitored from December 2018 to November 2019 by using a soil CO2 flux system (LI-8100A, LI-COR, Lincoln, NE). Results showed that Reyan No. 2 had the best promoting effect on soil respiration in orchards, followed by Ubon and natural grass growth. The relationship between soil respiration and soil temperature of 5-cm soil layer followed highly significant power function pattern for Stylo grass treatments (p < .01). The temperature sensitivity (Q10) of Reyan No. 2 was highest (1.75), followed by Ubon (1.46). Soil water, instead of temperature, was found to be the main factor of soil respiration in the grass orchard of latosol. This study proposes the main limiting factors of soil respiration in latosol orchards and recommends Reyan No. 2 as a grass variety for soil improvement. The finding has also enriched the theory and practice of soil improvement in latosol orchards. The higher Q10 (1.75) of Reyan No. 2 as obtained in this research may also have a certain effect on the soil carbon cycle of grass orchard of latosol. [ABSTRACT FROM AUTHOR]

[Objective] This study aimed to investigate the changes of aroma components in mango fruit at different post-harvest stages. [Method] The aroma components in 'Keitt' mango fruit at 3, 6, 9 and 13 d postharvest were extracted using head-space solid phase microextraction (HS-SPME) and analyzed by gas chro-matograph-mass spectrophotometer (GC-MS). [Result] The results showed that a total of 42 aroma compounds were identified from the mango samples at four stages. To be specific, monoterpene and sesquiterpene were the major components; at 3, 6, 9 and 13 d postharvest, the relative contents of terpene were 94. 24%, 98. 91%, 55. 32% and 95. 97%, respectively. [Conclusion] 1S-( + ) -3-carene is the characteristic aroma component in ripe fruit of 'Keitt' mango. The aroma of mango fruit is also affected by ester, alcohol and aldehyde compounds. [ABSTRACT FROM AUTHOR]