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Understanding the impacts and constraints of climate change on the geographical distribution of wild Akebia trifoliata is crucial for its sustainable management and economic development as a medicinal material or fruit. In this study, according to the first‐hand information obtained from field investigation, the distribution and response to climate change of A. trifoliata were studied by the MaxEnt model and ArcGIS. The genetic diversity and population structure of 21 natural populations of A. trifoliata were studied by simple sequence repeat (SSR) markers. The results showed that the most important bioclimatic variable limiting the distribution of A. trifoliata was the Mean Temperature of Coldest Quarter (bio11). Under the scenarios SSP1‐2.6 and SSP2‐4.5, the suitable area of A. trifoliata in the world will remain stable, and the suitable area will increase significantly under the scenarios of SSP3‐7.0 and SSP5‐8.5. Under the current climate scenario, the suitable growth regions of A. trifoliata in China were 79.9–122.7°E and 21.5–37.5°N. Under the four emission scenarios in the future, the geometric center of the suitable distribution regions of Akebia trifoliata in China will move to the north. The clustering results of 21 populations of A. trifoliata analyzed by SSR markers showed that they had a trend of evolution from south to north. [ABSTRACT FROM AUTHOR]

Amygdalin, a naturally occurring compound, is one of the main active ingredients of the Chinese raw bitter almond. The variation in amygdalin composition of seed kernels among the six almond species was determined, and relationships with geoenvironmental factors were analyzed. The amygdalin content exhibited great diversity, ranging from 0.0004 to 9.73 g/100 g. The highest level of amygdalin was detected in Tangut almond, with 5.45–9.73 g/100 g. The other kernels showed a range from 3.14 to 6.80 g/100 g in wild almond and from 3.00 to 4.22 g/100 g in longstalk almond. Amygdalin in common almond was almost undetectable. Factor analysis showed that amygdalin content in Prunus spp. kernels increased with altitude and decreased with the degree of aspect. Many environmental factors were closely related to amygdalin content, including annual precipitation (Bio12), UV intensity, and topsoil base saturation (T_BS), which all had a significant effect on amygdalin content. The amygdalin content is closely related to rainfall indicators, especially annual precipitation (Bio12), with the highest factor analysis value (3.63). Water regulates amygdalin in diverse ways. Since amygdalin is water-soluble, water can reduce the inhibitory effect of amygdalin on germination and regulate the synthesis of amygdalin at the late stage of germination by activating the amygdalin synthesis genes CYP79D16 and CYP71AN24. This study expands the understanding of amygdalin in almond resources and provides the direction for the regulation of amygdalin. [ABSTRACT FROM AUTHOR]

Almond resources are widely distributed in Central Asia; its distribution has not been studied in detail. Based on the first-hand data of field investigation, climate variables and chloroplast genome data, climatic characteristics of six almond species in China were analyzed, and the global distribution and evolutionary relationship were predicted. The six almond species are concentrated between 27.99°N and 60.47°N. Different almond species have different climatic characteristics. The climate of the almond species distribution has its characteristics, and the distribution of almond species was consistent with the fatty acid cluster analysis. All the test AUC (area under curve) values of MaxEnt model were larger than 0.92. The seven continents except for Antarctica contain suitable areas for the six almond species, and such areas account for approximately 8.08% of the total area of these six continents. Based on the analysis of chloroplast DNA and the distribution characteristics, the evolutionary relationship of the six almond species was proposed, which indicated that China was not the origin of almond. In this study, the construction of a phylogenetic tree based on the chloroplast genome and the characteristics of geographical distribution were constructed. The six almond species in China may have evolved from "Unknown almond species" through two routes. The MaxEnt model for each almond species provided satisfactory results. The prediction results can provide the important reference for Prunus dulcis cultivation, wild almond species development and protection. [ABSTRACT FROM AUTHOR]

As a source of genetic variation, almond germplasm resources are of great significance in breeding. To better reveal the mutation characteristics and evolution patterns of the almond chloroplast (cp) genome, the complete cp genomes from six almond species were analyzed. The lengths of the chloroplast genome of the six almond species ranged from 157,783 bp to 158,073 bp. For repeat sequence analysis, 53 pairs of repeats (30 bp or longer) were identified. A total of 117 SSR loci were observed, including 96 polymorphic SSR loci. Nine highly variable regions with a nucleotide variability (Pi) higher than 0.08, including rps16, rps16-psbK, atpF-atpH, rpoB, ycf3-rps4, rps4-ndhJ, accD-psaI and rps7-orf42 (two highly variable regions) were located. Based on the chloroplast genome evolution analysis, three species (P. tenella, P. pedunculata and P. triloba) and wild cherry (P. tomentosa) were grouped into clade I. Clade II consisted of two species (P. mongolica and P. tangutica) and wild peach (P. davidiana). Clade III included the common almond (P. dulcis), cultivated peach (P. persica) and GanSu peach (P. kansuensis). This result expands the researchers' vision of almond plant diversity and promotes an understanding of the evolutionary relationship among almond species. In brief, this study provides abundant resources for the study of the almond chloroplast genome, and has an important reference value for study of the evolution and species identification of almond. [ABSTRACT FROM AUTHOR]

As a source of genetic variation, almond germplasm resources are of great significance in breeding. To better reveal the mutation characteristics and evolution patterns of the almond chloroplast (cp) genome, the complete cp genomes from six almond species were analyzed. The lengths of the chloroplast genome of the six almond species ranged from 157,783 bp to 158,073 bp. For repeat sequence analysis, 53 pairs of repeats (30 bp or longer) were identified. A total of 117 SSR loci were observed, including 96 polymorphic SSR loci. Nine highly variable regions with a nucleotide variability (Pi) higher than 0.08, including rps16, rps16-psbK, atpF-atpH, rpoB, ycf3-rps4, rps4-ndhJ, accD-psaI and rps7-orf42 (two highly variable regions) were located. Based on the chloroplast genome evolution analysis, three species (P. tenella, P. pedunculata and P. triloba) and wild cherry (P. tomentosa) were grouped into clade I. Clade II consisted of two species (P. mongolica and P. tangutica) and wild peach (P. davidiana). Clade III included the common almond (P. dulcis), cultivated peach (P. persica) and GanSu peach (P. kansuensis). This result expands the researchers' vision of almond plant diversity and promotes an understanding of the evolutionary relationship among almond species. In brief, this study provides abundant resources for the study of the almond chloroplast genome, and has an important reference value for study of the evolution and species identification of almond. [ABSTRACT FROM AUTHOR]

Salix viminalis L., a dioecious species, is widely distributed in riparian zones, and flooding is one of the most common abiotic stresses that this species suffers. In this study, we investigated the morphological, anatomical, and physiological responses of male vs. female plants of S. viminalis to flooding. The results showed that the plant height and root collar diameter were stimulated by flooding treatment, which corresponded with higher dry weight of the stem and leaf. However, the dry weight of the underground part decreased, which might be due to the primary root having stopped growing. The little-influenced net photosynthesis rate (Pn) under flooding treatment could guarantee rapid growth of the aboveground part, while the unaffected leaf anatomical structure and photosynthetic pigment contents could ensure the normal operation of photosynthetic apparatus. Under a flooding environment, the production ratio of superoxide free radical (O2∙-) and malondialdehyde (MDA) contents increased, indicating that the cell membrane was damaged and oxidative stress was induced. At the same time, the antioxidant enzyme system, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and osmotic adjustment substances, involving proline (Pro) and solute protein (SP), began to play a positive role in resisting flooding stress. Different from our expectation, the male and female plants of S. viminalis performed similarly under flooding, and no significant differences were discovered. The results indicate that both male and female plants of S. viminalis are tolerant to flooding. Thus, both male and female plants of S. viminalis could be planted in frequent flooding zones. [ABSTRACT FROM AUTHOR]