Horticulture Environment and Biotechnology最新文献

Fruit shape is one of the important traits for quality evaluation, classification, and market grading of horticultural crops. In order to explore the genes regulating pear fruit shape formation, pear varieties ‘Huangguan’ and ‘Korla Fragrant Pear’ with significant differences in fruit shape were selected as experimental materials. Through morphological observation, measurement of fruit longitudinal diameter and fruit transverse diameter, and fruit shape index analysis of the pear fruit growth and development period, the formation of pear fruit shape during the young fruit period was preliminarily determined. By analyzing the transcriptome data of ‘Huangguan’ and ‘Korla Fragrant Pear’ at the young fruit stage, 8993 differentially expressed genes were obtained, and the majority of the genes were annotated to the plant hormone signaling pathway, among which gibberellin-related genes accounted for 13.4%. Spraying GA₃ at the full-bloom stage can significantly prolong the shape of oriental pear. The results of qRT-PCR showed that the expression level of the gibberellin metabolic pathway gene PbGA2ox11 in ‘Huangguan’ was significantly higher than that in ‘Korla Fragrant Pear’. GA₃ treatment inhibited the expression of this gene in ‘Korla Fragrant Pear’, while PP₃₃₃ promoted the expression. It was speculated that PbGA2ox11 was most likely to regulate the shape of pear fruit by regulating gibberellin metabolism. This study provides a new method for studying fruit shape via the analysis of the gibberellin synthesis metabolic pathway, new resources for the rational use of plant growth regulators, and theoretical and technical support for cultivating excellent fruit shape.

As a volatile hormone signal, methyl jasmonate (MeJA) can regulate the biosynthesis of secondary metabolites. But in floral fragrance, the effect and mechanisms of MeJA on monoterpenes, the major components of many plants, are largely unknown. In this paper, we measured the release of monoterpenes from petals of Lilium ‘Siberia’ after MeJA treatment, as well as the expressions of monoterpene pathway genes and Lilium coronatine-insensitive (LiCOI1) gene. Then the LiCOI1 gene was cloned, and using virus-induced gene silencing (VIGS) technology, its function in monoterpene biosynthesis in response to MeJA was validated. The results showed that MeJA significantly improved the release amounts of myrcene, ocimene, and linalool. The expression levels of synthase genes [Lilium myrcene synthase (LiMYS), Lilium ocimene synthase (LiOCS), as well as Lilium linalool synthase (LiLIS)], two pathway genes [Lilium 1-deoxy-D-xylulose 5-phosphate synthase (LiDXS) and Lilium 1-deoxy-D-xylulose-5-phosphate reductoisomerase (LiDXR)] were enhanced. Moreover, the LiCOI1 gene exhibited a remarkably increased expression level, which suggested its signaling role. Based on the analysis, the full length of LiCOI1 gene was 1809 bp, whose deduced protein contained 602 amino acids and was mainly located in the nucleus. Silencing the expression of LiCOI1 in petals significantly depressed not only the gene expressions of LiMYS, LiOCS, LiLIS, LiDXS, and LiDXR, but also the release amounts of myrcene, ocimene, and linalool. These results confirm that LiCOI1 plays an important signaling role in MeJA-induced enhancement of monoterpene biosynthesis in Lilium ‘Siberia’.

The importance of involving genetic diversity in breeding has been emphasized for the sustainable and stable utilization of crop genetic resources and preparation for unpredictable future environments. The black raspberry fruit from the genus Rubus is highly consumed owing its flavor and health benefits, but the genetic basis of its cultivars is very limited with insufficient genetic information available. Therefore, breeding programs must focus on the exploitation of genetic diversity of wild crop relatives. We assessed the genetic diversity, population differentiation, and genetic structure of 11 wild relatives of R. coreanus Miq. using 10 microsatellite markers to collect valuable genetic information and propose enhanced strategies for development of breeding populations. The observed and expected heterozygosity were 0.493 and 0.520, respectively. Genetic differentiation among the populations was 0.109. The Mantel test confirmed that wild R. coreanus populations differentiated following isolation by distance. Moreover, Bayesian clustering analysis showed that R. coreanus populations consisted of three genetic clusters, distribution of those showed a geographical tendency. Based on the genetic diversity, private allele frequency, and genetic structure results, we suggest to preferentially include the Chiak, Hamyang, and Jeju populations for construction of a breeding population of the Korean black raspberry.

Phalaenopsis ‘Sogo Vivien’ is a hybrid orchid that can produce a mutant with foliar variegation. Variegation can be divided into structural-type and pigment-type variegation. Foliar variegation was mostly caused by mutations in plastid genes. Even though there are various studies on foliar variegation in other plants, studies on foliar variegation in orchids are quite limited. This study aimed to determine the variegated leaf phenotype characteristics and their cause in P. ‘Sogo Vivien’. This study observed the anatomy of variegated leaves by comparing the green and white parts of the leaf, measured the concentration of chlorophyll pigments, and detected leaf starch content between both parts. In addition, polymorphism analysis was also performed on the VAR2 gene partial sequences. Based on leaf anatomy structure, the difference between variegated zones is only in the number of chloroplasts, the diameter of parenchyma cells, and chloroplasts. The chloroplast diameter within the white part is smaller than the green part. The chloroplasts’ diameters in the green part are two times larger than the white part, with four times more in amount. The two parts were formed due to differences in the distribution pattern of functional chloroplasts in the leaves. The concentration of chlorophyll in the green part is higher than in the white part, a characteristic of the chlorophyll-type variegation. The green parts have more starch grains than the white parts. Stomata distance between variegated zones on the abaxial side is different, and it was suggested as a distinctive character between variegated zones. A thymine insertion in exon 1 contributed to nonsense and missense mutations on the VAR2 gene isolated from the white part. This mutation caused the amino acid motif to change from KAKFQ to KA—Q. This mutation is suggested to cause the variegated leaf phenomenon in P. ‘Sogo Vivien’.

Cold storage is a widely employed technique for prolonging the post-harvest shelf life of ‘Nanguo’ pear. Nonetheless, this method has been observed to diminish the fruit’s aromatic properties. Given the significance of aroma in determining the volatile quality, this research endeavors to examine the impact of methyl jasmonate (MeJA) in preserving aroma content, while also delving into the underlying molecular mechanisms that contribute to its efficacy. Upon observing the metabolic changes, it was found that the pear, sprayed MeJA, could keep higher the content of aroma, ascorbic acid, polyphenol, oleic acid, linoleic acid, and linolenic acid than the control, but stearic acid and H₂O₂ were decreased. The enzyme activities of lipoxygenase (LOX), alcohol acyl transferase (AAT), and catalase (CAT) were enhanced by MeJA treatment, but the polyphenol oxidase (PPO) was inhibited. Moreover, the gene expression levels of LOX, AAT, CAT, stearoyl-ACP desaturase (SAD), and fatty acid desaturase 2 (FAD2) were promoted by MeJA. It is reasonable that sprayed MeJA was a reliable method for inhibiting aroma loss and triggered unsaturated fatty acid and reactive oxygen metabolisms.

Basil (Ocimum basilicum L.) is a highly important medicinal plant. In this study, the interactional effects of water deficit and melatonin application on growth and physio-biochemical characteristics of basil were investigated. The treatments included three levels of irrigation (100, 75 and 50% of field capacity) and three melatonin concentrations (0, 50 and 100 µmol). Drought stress decreased the dry weight of plants but application of 100 µmol melatonin markedly increased dry weight under these conditions. Melatonin profoundly enhanced plant drought tolerance by stimulating the antioxidant enzymes (catalase, phenylalanine ammonia-lyase, ascorbate peroxidase and polyphenol oxidase) activities and secondary metabolites (total phenol, flavonoid and anthocyanin contents). Furthermore, melatonin application reduced lipid peroxidation and increased the relative water content and photosynthetic pigments, resulting in an improvement of plant dry matter. It is concluded that foliar spraying with melatonin induced the pre-adaptive responses to drought stress followed by regulating antioxidant defense mechanisms.

In the present study, it was aimed to determine the effects of preharvest oxalic acid (OA) treatments on the biochemical content and quality of minimally processed leeks during storage. For this purpose, leeks were treated with solutions containing 0 (control), 1, 2 and 3 mM OA and 0.1% Tween-20 with a pump 6, 4 and 2 weeks before harvest. The packaged leeks were stored at 0 °C and 90 ± 5% relative humidity (RH) for 50 days. After the cold storage, the leeks were kept at 20 °C and 60 ± 5% RH for 3 days to determine the shelf-life. The effects of OA treatments on the weight loss, external appearance and bioactive compounds were remarkable. At the end of storage, the losses of ascorbic acid (AsA) content were determined as 55.53% in the control group and 22.89% in the 3 mM OA treatment. Similarly, the decrease in total phenolic (TP) content and antioxidant activity (AOA) in the control group was 37.34% and 45.70%, respectively, while these values were determined as 26.94% and 32.65% in the 3 mM OA treatment, respectively. With 3 mM OA treatment, the high dose in this study, the AsA, TP, and AOA contents of leeks were better preserved. The change in the external appearance scores at the end of cold storage was determined as 46.33% in the control group whereas it was determined between 31.44% (2 mM OA) and 42.55% (1 mM OA) in OA treatments. As a result, OA-treated and minimally processed leeks were successfully stored for 50 days at 0 °C and 90 ± 5% RH. Moreover, the efficacy of OA increased in a dose-dependent manner in the study.

Jujube (Ziziphus jujuba Mill.) is a plant belonging to the genus Ziziphus of the family Rhamnaceae. Z. jujuba is generally rich in nutrients—vitamin C, thiamin, and riboflavin—making it an excellent source of functional food. Z. jujuba cultivation has a long history, resulting in the creation of numerous cultivars, and the economic value of this plant has recently been on the rise. Therefore, there is a need for easy and accurate methods to distinguish the cultivars. We developed insertion or deletion (InDel) markers using chloroplast (CP) DNA to identify Z. jujuba cultivars. A total of 192 InDel loci were found and 21 InDel markers were developed. Twenty-two InDel markers were used for diversity analysis, including the Zj-InDel-1 marker developed in the previous study. The size of the InDel loci varied from 4 to 200 bp. The maximum value of polymorphism information content (PIC) was 0.35, the minimum value was 0.03, and the average was 0.31. The 61 Z. jujuba cultivars were grouped into 8 CP types by the 22 CP InDel markers. The ‘Dongjo’, ‘Sanjo’, ‘Tibetwang’ and ‘Wolgwang’ cultivars were classified independently among the 61 cultivars. The InDel markers developed in this study could be used for cultivar identification and breeding of Z. jujuba.

Ginseng has some chronic problems caused by the conventional shading structure. Although greenhouse cultivation has been expanded as an affordable alternative solution, no suitable colored woven film (WF), considering the durability, environmental changes, and growth parameters, has yet not been developed. After checking the light reflectance, solar light transmittance, and spectral photon flux distribution of various colored WFs, pearl WF (high light reflectance of 90% and close to 1.0 B/R light ratios) is expected to have positive effects such as increasing growth by manipulating B/R light ratios including temperature reduction due to albedo difference was mass-produced. In this study, 85% two-layered black shade net with general polyethylene film (black PE), blue WF, and pearl WF were covered on the greenhouses to investigate microclimate and growth ginseng. Spectral light through the films indicated that the blue (B) to red (R) light ratios of pearl WF (1.07–1.50) were lower than that of the black PE (0.83–1.69) and blue WF (1.94–8.68) regardless of the weather, whereas the difference in red to far-red light among the films was less than 25%. The air temperature at 2 pm of the pearl WF was 0.6–2.4^oC lower than that of the black PE and blue WF in the summer. The plants grown under the pearl WF had an overall increase in the growth of the aerial part, including the leaf area, more than that of the black PE or blue WF, thereby having the most significant root weight at the time of final harvest. Aside from the targeted product, the total chlorophyll content of the ginseng grown under blue WF was maintained at a high level. The results from the experiment summarized that the pearl WF is recommended to increase the root weight of ginseng because it can ensure durability and provide a cost-effective approach for manipulating microclimate properties to promote their growth.

Increasing climatic temperatures and precipitation in the autumn may lead to increased injury and decay during extended storage of mandarin fruits. In this study, we examined the internal fruit quality, rind color, ultrastructure of the peel, inorganic composition of albedo, and flavonoid contents of the flavedo at harvest in the early-maturing cultivar satsuma mandarin ‘Miyagawa Wase.’ Fruits were treated with a mixture of gibberellic acid (GA; 25 mg L^− 1) and prohydrojasmon (PDJ; 100 mg L^− 1) denoted as (GP), only GA (25 mg L^− 1), and only PDJ (100 mg L^− 1) in August and September. Specific gravity and titratable acidity (TA) of the GA-treated fruits were higher than those of the non-GA-treated fruits (PDJ and control), while lower ratios of soluble solids content (SSC) and TA were observed. The GA-treated fruits’ L* (lightness), a* (bluish-green/red-purple hue component), b* (yellow-blue hue component), and C* (chroma) values were significantly lower than those of non-GA-treated fruits. In particular, a* value of GP (0.5) was significantly lower than that of control (24.6). The non-GP-treated fruits had higher epicuticular wax on the peel than GP-treated fruits. The distributions of N, P, and Mg in the GA-treated fruits were higher than those in non-GA-treated fruits. Nobiletin and tangeretin contents of the flavedo were the highest in the GP treatment, followed by the GA, PDJ, and control treatments. The occurrence of rind disorder after 20 d of storage was the lowest in GP, whereas PDJ and control treatments showed 18% over. These results indicate that the combined treatment with GA and PDJ has a more substantial effect than treatment with only GA or PDJ in controlling peel ripening at harvest and rind disorder after storage in satsuma mandarin fruits.