Magnolia lucida (Magnoliaceae) is classified as an endangered species by the International Union for Conservation of Nature. It has high commercial value owing to its attractive tree shape and flowers. We adopted an excellent genotype of M. lucida as the parent material and established a mini-cut orchard through grafting to provide trunk shoots explants over the long-term. Optimal sterilization was achieved using a combination of 75% ethanol for 30 s, one percent benzalkonium bromide for five minutes, and 0.1% mercuric chloride for five minutes. Modified Murashige and Skoog medium (ML) was the optimal medium for the growth of M. lucida. Addition of one mg/L of 6-benzyl adenine (BA) and 0.05 mg/L of α-naphthaleneacetic acid (NAA) to the medium increased the shoot induction rate to 95.56%, and the ML medium containing 0.4 mg/L BA and 0.04 mg/L NAA achieved the maximum multiplication rate (284.56%). Dark treatment for seven days, followed by continuous light treatment could better resolve the challenge of difficult rooting in M. lucida plants. Using random amplified polymorphic DNA and inter simple sequence repeat markers, we confirmed the genetic uniformity and stability of the regenerated plants. Our protocol should be helpful for the propagation and conservation of this endangered plant.

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Jujubes (Ziziphus jujuba Mill.) are among the main agroeconomically important crops in Xinjiang, China, and those from this region have the highest production worldwide. However, the reason for the high quality of the jujubes in the region is unknown. In our current research, the total phosphorus (P), total nitrogen (N), organic matter (OM), available P, alkaline N and quick potassium (K) were quantitatively analyzed in soils collected from orchards in 11 geographical locations, counties or cities, in Xinjiang. Meanwhile, the P, total triterpenoids, soluble solids, polysaccharide and cyclic adenosine monophosphate (CAMP) contents were also used to indicate fruit quality. Based on the analyzed data, principal component analysis (PCA) and multiple regression analysis revealed a high correlation between soil nutrients and the quality of the Jun jujube, which was used as an example. Specifically, the total P and quick K contents significantly differed among the orchard soils. Moreover, they significantly affected fruit quality. Total P significantly affected the soluble solids and total triterpenoids contents and was negatively correlated with the former and positively correlated with the latter. In addition, the soluble solids and total triterpenoids contents were significantly affected by the quick K content; as the quick K content increased, the soluble solids content gradually increased, while the total triterpenoids content decreased. According to the response surface model, we suggest that when the total P and quick K contents in the soil in Xinjiang were 0.76 g/kg and 365.04 mg/kg, respectively, the optimal fruit quality was obtained. Therefore, two-dimensional analysis of fruit quality and soil nutrients showed that it is necessary to increase the total P and quick K contents in the soil used to grow jujubes in Xinjiang.

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