Volatile components of nine litchi cultivars (10 samples) with high commercial value from Southern China were investigated by means of gas chromatography-mass spectrometry combined with headspace solid phase microextraction. A total of 96 volatiles were detected, of which 43 were identified. Seventeen common volatiles in all the samples included linalool, cis-rose oxide, alpha-terpineol, beta-citronellol, geraniol, p-cymene, ethanol, 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol, 1-hexanol, (E)-2-hexen-1-ol, 2-ethyl-1-hexanol, 1-octen-3-ol, 1-octanol, ethyl acetate, p,alpha-dimethylstyrene and 3-tert-butyl-4-hydroxyanisole. Although the volatile composition and concentration varied between these cultivars, the components with the highest OAVs in most cultivars were still cis-rose oxide, trans-rose oxide, 1-octen-3-ol, and geraniol. Two Huaizhi samples from two producing areas exhibited similar volatile profiles, and significantly different from other cultivars according to cluster analysis performed on amounts of major volatile components.

map with 6970 markers and a total map length of 1823.1 centimorgan (cM), on which 837 QTLs were projected. These QTLs were then integrated into 87 meta-quantitative trait loci (MQTLs) by meta-analysis, and the 95 % confidence intervals (CI) of them were smaller than the mean value of the original QTLs. Also, 30 MQTLs covered 47 of the 54 QTLs detected from the cross between Nipponbare and H71D in this study. Among them, the two major and stable QTLs, spp10.1 and sd10.1, were found to be included in MQTL10.4. The three other major QTLs, pl3.1, sb2.1, and sb10.1, were included in MQTL3.3, MQTL2.2, and MQTL10.3, respectively. A total of 21 of the 87 MQTLs' phenotypic variation were >20 %. In total, 24 candidate genes were found in 15 MQTLs that spanned physical intervals <0.2 Mb, including genes that have been cloned previously, e.g., EP3, LP, MIP1, HTD1, DSH1, and OsPNH1. However, it would be beneficial to identify a greater number of candidate genes from these MQTLs. Mining new genes that modulate yield and its related traits would assist researchers to better understand the relevant molecular mechanisms. The MQTLs found in this study that have small physical and genetic intervals are useful not only for marker-assisted selection and pyramiding, but they also provide important information of rice yield and related gene mining for future research.Keywords QTL analysis · Meta-analysis · Rice panicle traits · Yield · MQTL Communicated by B. Yang.Y. Wu and M. Huang are contributed equally to this work. Electronic supplementary materialThe online version of this article (

Under salinity, Vitis spp. rootstocks can mediate salt (NaCl) exclusion from grafted V. vinifera scions enabling higher grapevine yields and production of superior wines with lower salt content. Until now, the genetic and mechanistic elements controlling sodium (Na ) exclusion in grapevine were unknown. Using a cross between two Vitis interspecific hybrid rootstocks, we mapped a dominant quantitative trait locus (QTL) associated with leaf Na exclusion (NaE) under salinity stress. The NaE locus encodes six high-affinity potassium transporters (HKT). Transcript profiling and functional characterization in heterologous systems identified VisHKT1;1 as the best candidate gene for controlling leaf Na exclusion. We characterized four proteins encoded by unique VisHKT1;1 alleles from the parents, and revealed that the dominant HKT variants exhibit greater Na conductance with less rectification than the recessive variants. Mutagenesis of VisHKT1;1 and TaHKT1.5-D from bread wheat, demonstrated that charged amino acid residues in the eighth predicted transmembrane domain of HKT proteins reduces inward Na conductance, and causes inward rectification of Na transport. The origin of the recessive VisHKT1;1 alleles was traced to V. champinii and V. rupestris. We propose that the genetic and functional data presented here will assist with breeding Na -tolerant grapevine rootstocks.

C6 compounds are the major fraction of the volatile profiles of grape berries, contributing the typical 'green' aroma to the grape and wine. Hydroperoxide lyase (HPL) catalyzes the cleavage of fatty acid hydroperoxides to produce C6 compounds. Two hypothetical genes, VvHPL1 and VvHPL2 were cloned from grape berries (Vitis vinifera L. Cabernet Sauvignon). Bioinformatics analysis revealed that the proteins encoded by these two genes both belong to subfamily of cytochrome P450 and contain typical conserved domains of HPLs, and have high identity with HPLs from other plants. Prokaryotically-expressed VvHPL1 and VvHPL2 with thioredoxin-6xHis-fusion partner were confirmed to have enzymatic activity. VvHPL1 is specific for 13-HPOD (T) producing C6 aldehydes with relatively higher activity and VvHPL2 catalyzes the cleavage of both 9- and 13-hydroperoxides producing C6 aldehydes and C9 aldehydes respectively. Analysis of real time-PCR showed that VvHPL2 was highly expressed in the leaves and the flowers of the grapes, while relatively low transcript abundance was detected in the berries, tendril and stems; VvHPL1 had high expression in all detected tissues. During grape berry development, the expression of these two isogenes presented similar trends with a rapid increase after veraison and a decrease at full-ripen stage, which roughly corresponded to the accumulation of their volatile products. These data lay an essential foundation for further study on the accumulation and control of C6 volatiles in grape berries.