When wheat is subjected to heat stress during grain filling, metabolic adaptation reallocates resources to deposition of reserves and prioritizes a stable filling rate.

We conclude that there have been huge population migrations from surrounding lowland onto the Tibetan Plateau via the Tibetan-Yi Corridor since the initial formation of Tibetans probably in Neolithic Time, which leads to the current genetic structure of Tibeto-Burman speaking populations.

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Fifty-two SSR markers were used to evaluate the genetic diversity of 33 Qinghai-Tibetan wild barley accessions, 56 landraces collected primarily from other parts of China, and 1 Israeli wild barley accession. At the 52 SSR loci, 206 alleles were detected for the 90 accessions, among which 111 were common alleles. The number of alleles per locus ranged from 1 to 9, with an average of 4.0. Polymorphism information content (PIC) values ranged from 0 to 0.856 among all the markers, with an average of 0.547. The PIC value of Qinghai-Tibetan wild barley varied from 0 to 0.813 with an average of 0.543, while in landraces, the markers showed a range of 0 to 0.790 with an average of 0.490. The SSR markers could clearly differentiate the Qinghai-Tibetan wild barley from the landraces. Twenty-four unique alleles were observed in Qinghai-Tibetan wild barley, and the frequency of unique alleles in Qinghai-Tibetan wild barley was about 2.1 times higher than that in the landraces, on average. Five of the 7 chromosomes had more unique alleles in the Qinghai-Tibetan wild barley, but chromosome 2H had more unique alleles in the landraces. The presence of many unique alleles may reflect the adaptation of this barley germplasm to diverse environments and production systems.

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China has a large barley germplasm collection which has not been well characterized and is therefore underutilized. The Bmy1 locus encoding the β-amylase enzyme on chromosome 4H has been well characterized in the worldwide barley germplasm collections due to its importance in the malting and brewing industry. The Bmy1 locus was chosen as an indicator to understand genetic potential for improvement of malting quality in Chinese landraces and Tibetan wild barley. The genetic diversity of 91 barley accessions was assessed using allele specific Multiplex-ready molecular markers. Eight accessions were further sequenced, based on the Multiplex-ready marker diversity for Bmy1 in the germplasm. Six of the eight accessions clustered together in a unique group, and showed similarities to ‘Haruna Nijo’, wild barley accession PI296896 and ‘Ashqelon’. Sequence comparisons with the known Bmy1 alleles identified not only the existing 13 amino acid substitutions, but also a new substitution positioned at A387T from a Chinese landrace W127, which has the highest β-amylase activity. Two new alleles/haplotypes namely Bmy1-Sd1c and Bmy1-Sd5 were designated based on different amino acid combinations. We identified new amino acid combination of C115, D165, V233, S347 and V430 in the germplasm. The broad variation in both β-amylase activity and amino acid composition provides novel alleles for the improvement of malting quality for different brewing styles, which indicates the high potential value of the Chinese landraces and Tibetan wild barley.

Wild strawberries are grown widely in southern Shaanxi (China), but information about their sensory and chemical characteristics is scant. In this work, exploratory research was conducted to correlate the results of instrumental analyses of the aroma compounds in wild strawberry wine and their sensory perception. Headspace solid-phase micro extraction (HS-SPME) was used for the pretreatment, and gas chromatography-mass spectrometry (GC-MS) was to analyze the aroma compounds. A total of 78 volatile compounds were identified, including 25 alcohols, 25 esters, four acids, five ketones, four aldehydes, nine terpenes, five phenols, and one styrene, but only 74 could be quantified. Odor activity values (OAVs) were determined for 21 odor-active compounds. Six were identified as the characteristic aroma substances for the wild strawberries from a principal component analysis (PCA) of the composition, in particular methyl 2-methylbutyrate, ethyl 2-methylbutyrate, ethyl 3-methylbutyrate, (E)-3-hexen-1-ol, 1-octen-3-ol, and phenylacetaldehyde. Sensory evaluation by a trained panel using descriptive analysis also revealed that sweetness was the main attribute in wild strawberry and its wines, and differences in varietal flavors were also observed. Wild strawberry wine is proved to exhibit a high quality of its fruit flavor, and thus winemaking is a performable practice for wild strawberry. ARTICLE HISTORY