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The germination rate of conventional seed treatment for Acer fabri is relatively low. It is of great significance to study seed propagation methods to improve germination rate of A. fabri. The seeds of A. fabri should be harvested in November and stored in wet sand till February or March next year. Cool storage or room temperature storage is not conducive to the germination of A. fabri. After pregermination, the seeds can be sown in sandy soil and the germination rate could reach more than 70%. The cutting scions of A. fabri may not be processed, or may be treated by 100 PPM Indolebutyric acid on the scion base, and the rooting rate reached 94%, the average number of lateral roots per plant reached 3.6, and the average lateral root length reached 5.3 cm. Too many roots generated while the base of scions was treated with 1000 PPM or 2000 PPM Indolebutyric acid, and the plantlets grew slowly. A. fabri contains high endogenous hormone, so low concentration IBA or no growth regulator treatment is beneficial to root and later growth. The results provide practical mass production techniques for A. fabri.

The frequency and intensity of heat waves (HWs) has increased in subtropical regions in recent years. The mechanism underlying the HW response of subtropical trees remains unclear. In this study, we conducted an experiment with broad-leaved Schima superba (S. superba) and coniferous Cunninghamia lanceolata (C. lanceolata) seedlings to examine HW (5-day long) effects on stem water transport, leaf water use efficiency (WUE), morphology and growth, and to elucidate differences in the responses of both species. Our results indicated that HWs can significantly reduce hydraulic conductivity in both species. C. lanceolata experienced significant xylem embolism, with the percentage loss of conductivity (PLC) increasing by 40%, while S. superba showed a non-significant increase in PLC (+25%). Furthermore, HW also caused a reduction in photosynthesis rates (An), but transpiration rates (Tr) increased on the 5th day of the HW, together leading to a significant decrease in leaf WUE. From diurnal dynamics, we observed that the HW caused significant decrease of S. superba An only in the morning, but nearly the all day for C. lanceolata. During the morning, with a high vapor pressure deficit (VPD) environment, the HW increased Tr, which contributed a lot to latently cooling the foliage. In comparing the two tree species, we found that HW effects on S. superba were mostly short-term, with leaf senescence but limited or no xylem embolism. The surviving S. superba recovered rapidly, forming new branches and leaves, aided by their extensive root systems. For C. lanceolata, continued seedling growth initially but with subsequent xylem embolism and withering of shoots, led to stunted recovery and regrowth. In conclusion, apart from the direct thermal impacts caused by HW, drought stress was the main cause of significant negative effects on plant water transport and the photosynthetic system. Furthermore, S. superba and C. lanceolata showed clearly different responses to HW, which implies that the response mechanisms of broad-leaved and coniferous tree species to climate change can differ.

Altingia chinensis is an important native broad-leaved tree in southern China. Its wood can be used as an excellent edible fungus culture medium, in addition, aromatic oil can be extracted for medi...

Tea tree oil is extracted from the leaves and twigs of Melaleuca alternifolia (Maiden & Betche) Cheel, and it is widely used in medicines, food preservatives, cosmetics and health care products. Traditional propagation of M. alternifolia from seeds does not necessarily transfer the desired characteristics from their mother trees, the seedlings are not uniform, and the multiplication rate from cuttings is relatively low. For these reasons, it is necessary to develop tissue culture techniques for this species. This study showed that an efficient explant initiation medium for M. alternifolia was MS 1/2 + BA 0.6 mg L−1 + NAA 0.1 mg L−1 + sucrose 30 g L−1, which yielded a 75.9 % initiation rate. An efficient multiplication medium was MS + BA 0.3 mg L−1 + NAA 0.15 mg L−1 + sucrose 30 g L−1, which yielded a 4.3 multiplication rate and 3.2 cm shoot length. The rooting medium was MS 1/2 + IBA 0.1–0.25 mg L−1 + sucrose 15 g L−1, which yielded a 100 % rooting rate, 2.94–3.32 roots per individual and 1.36–1.44 cm root length. Local red-core soil was suitable as a transplant medium, and yielded 98 % survival. This study improved the tissue culture technique for mass-propagation of M. alternifolia, enabling the production of high quality plants for market.

Semiliquidambar cathayensis is a semi-evergreen broad-leaved tree species distributed in southern China. In 1999, it was approved and published as a national secondary protected plant. We obtained the complete chloroplast genome sequence of S. cathayensis by Illumina sequencing data. The complete chloroplast sequence is 160,430 bp, include large single-copy (LSC) region of 88,991 bp, small single-copy (SSC) region of 18,917 bp, and a pair of invert repeats (IR) regions of 26,261 bp. Plastid genome contain 133 genes, 86 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis showed that S. cathayensis is closely related to Liquidambar formosana.

In breeding programs, the variations and relationships among main traits need to be understood to develop selection and breeding strategies. Resin is considered as one of most important non-timber production of P. massoniana which can privides terpenes used in the chemical industry. The present study assessed the genetic variations in growth, morphologic traits, and resin yield, as well as the phenotypic and genetic correlations between these traits of 45 half-sib families of eight-year-old Pinus massoniana trees. All traits show highly significant family effects. The individual heritability for diameter at breast height (DBH) was the highest (hi 2=0.55). Heritabilities for resin yield, tree height, crown depth, and the height to the live crown were slightly lower than DBH, ranging from 0.32 to 0.45. The other traits were under weak genetic control and heritabilities ranged from 0.17 to 0.20. All growth and morphologic traits were significantly correlated genetically with resin yield. Number of living branches had the highest genetic correlation with resin yield (rg=0.99), followed by DBH and number of living whorls (rg=0.73 and 0.70). Only a moderate positive genetic correlation with resin yield was found with the other traits (rg=0.47-0.57), except for height under the living branches (rg=-0.45). The results of this study indicate that both resin yield and growth can be improved simultaneously in the next generation. Of the traits assessed DBH was the optimum trait for indirectly selecting high-yielding resin trees.

Osmotin plays an important role in plant response to low temperature and pathogen infection . To date l ittle is known on existence and full function of OSM genes in genome-wide. I n this study, based on an OSM expression sequence tag identified from a drought-treated subtractive library, StOSMs in the potato genome were identified and characterized in response to a water deficit gradient. BLAST and bioinformatic analysis revealed that there are at least eleven StOSMs in the potato genome . Among eleven StOSMs ,eight StOSM mRNAs accumulated in leaf at the drought-lethal critical point (DLP ) were at least 4-fold higher than in the control. The peak StOSM- 8E mRNA accumulation was 49-fold higher than the control. Three StOSM mRNAs in leaf at DLP were 9.2-f old lower than in the control. This result of qRT-PCR quantification was identical with the FPKM values of all eleven StOSMs examined in the the Potato Genome Sequence database (PGSD) . In conclusion, water deficiency does induce the regulation of the expression of the eleven StOSMs. Either up or downregulated by water deficiency, StOSM s play a positive role in enhancing potato tolerance to drought stress. Therefore, osmotins can be considered to be drought responsive molecules involved in withstanding water deficits. The result provides an evidence to reveal how potato adapts to drought stress.