Horticulture, Environment, Biotechnology

Correction to: Phylogeny and genetic variation in the genus Eranthis using nrITS and cpIS single nucleotide polymorphisms The original version of this article unfortunately contained a mistake. The name of Chin-Sung Chang was presented incorrectly. The corrected author list is given above.

Identification and development of a core set of informative genic SNP markers for assaying genetic diversity in Chinese cabbage Abstract Rapid, economical, and reliable genotyping is an important requirement for germplasm analysis and cultivar identification in crop species. Chinese cabbage (Brassica rapa L. subsp. pekinensis (Lour.) Hanelt) originated in China and is now an economically important vegetable crop worldwide, especially in East Asia. In this study, we evaluated 1167 single nucleotide polymorphisms (SNPs) among 166 representative Chinese cabbage inbred lines using a KASP genotyping assay. On the basis of polymorphisms and principal component analysis, we selected 60 core SNPs distributed on all Brassica rapa chromosomes with allele frequencies sufficiently balanced so as to provide adequate information for genetic identification. The core set of SNPs was used for construction of a neighbor-joining dendrogram, in which the 166 inbred lines were clustered into spring, summer, and autumn ecotype groups. Clustering of the ecotype groups was better resolved than that achieved with 1167 and 360 polymorphic SNP datasets. Stability and resolution of the core SNP markers were tested using 178 commercial hybrid Chinese cabbage cultivars to confirm their utility in genetic identification. The set of 60 informative and stable SNP markers showed high discriminatory power and relatively uniform genomic distribution (4–9 markers per chromosome). The SNPs represent a cost-efficient and accurate marker set for germplasm analysis and cultivar identification and are suitable for molecular marker-assisted breeding in Chinese cabbage.

Differential responses of walnut cultivars to cold storage and their correlation with postharvest physiological parameters Abstract In this study, we screened eight walnut (Juglans regia L.) cultivars ('Xifu2', 'Shaanhe', 'Weina', 'Xiangling', 'Xiluo3', 'Xifu1', 'Liaoning4', and 'Qingxiang') in order to establish reliable selection criteria for storage-tolerance. Fresh walnut fruit were stored at 0 ± 0.5 °C and 70–80% relative humidity. Browning index, postharvest physio-biochemical characteristics, acid value, and sensory quality were measured. The results showed that 'Xifu2', 'Shaanhe', and 'Weina' developed browning early and quickly and storage was terminated for these cultivars at 60 days. 'Xiluo3', 'Xifu1', 'Liaoning4', and 'Qingxiang' had a slow browning rate and storage was terminated at 72 days. 'Xiangling' developed browning at a medium rate and storage was terminated at 72 days. Correlation analysis suggested that the terminal browning index of each cultivar positively correlated with lipoxygenase activity at 18 days of storage, polyphenol oxidase activity at 18–30 days, malondialdehyde content at 18 days, and the respiration rate at 42 days, while it negatively correlated with the total phenolic content at 18 days and phenylalanine ammonia lyase activity at 12 days. The storage tolerance of each cultivar was evaluated according to the terminal browning index, acid value, and sensory quality. Comprehensive evaluation and cluster analysis were performed to rank the cold storage tolerance of the eight cultivars as follows: 'Qingxiang' and 'Xifu1' > 'Liaoning4' and 'Xiluo3' > 'Xifu2' and 'Xiangling' > 'Shaanhe' and 'Weina'. In conclusion, cultivars used for fresh in-husk walnut fruit with lower levels of membrane peroxidation and phenol oxidation, and higher level of phenol synthesis around 18 days of storage would be suitable candidates for cold storage. 'Qingxiang' and 'Xifu1' were selected as storage-tolerant cultivars.

Effect of pine wood biochar mixed with two types of compost on growth of bell pepper ( Capsicum annuum L.) Abstract The purpose of this study was to evaluate the biochar from fast pyrolysis of pine wood mixed with manure compost or vermicompost as a potential container substrate to replace peat moss. Seven biochar substrates were compared to the control (a commercial substrate; 0B) in container cultivation of bell pepper (Capsicum annuum L.): 100% biochar (100B), 90% biochar + 10% manure compost (90B10C; by volume), 80% biochar + 20% manure compost (80B20C), 70% biochar + 30% manure compost (70B30C), 90% biochar + 10% vermicompost (90B10V), 80% biochar + 20% vermicompost (80B20V), and 70% biochar + 30% vermicompost (70B30V). The physical characteristics of the container substrate (total porosity, container capacity, air space, and bulk density) were tested using NCSU porometers. The electrical conductivity (EC) and pH of container substrate leachates were measured according to the pour-through method on 34, 41, 62, and 83 days after planting (DAP). Growth index was measured on 34, 41, 48, 55, 62, 69, 76, and 83 DAP. Leaf SPAD value, net photosynthesis rate, total leaf area, and stem diameter were measured at week 11. Dry weight and yield were measured at the flowering (72 DAP) and harvesting (113 DAP) stages. The control showed the highest container capacity (59.2%) and the lowest air space (14.1%), with the opposite results observed on 100B. Control had pH values within 6.0–7.0 for optimum pepper growth, while container substrates with biochar resulted in a pH less than 6.0 from 41 to 83 DAP. EC in control at 34 DAP was approximately four times greater than values observed on the other substrates. EC of 70B30V slightly increased between 34 and 41 DAP, and the lowest EC was observed on 100B. SPAD value and net photosynthesis rate were the greatest on plants grown in control. The total leaf area, stem diameter, growth index, vegetative (stem + leaf) and flower dry weights, and yield were the highest in control, followed by 70B30V, 80B20V, and 90B10V, with the lowest in 100B.

Storage and growth temperatures affect growth, flower quality, and bulb quality of Hippeastrum Abstract The effects of storage and growth temperatures on growth, flower quality, and bulb quality of Hippeastrum sp. were studied. Bulbs of Hippeastrum sp. 'Apple Blossom' with circumferences in the range of 22–24 cm were selected and stored for 12 weeks at one of three different temperatures (i.e., room temperature [RT: 30 ± 2 °C], 13 ± 2 °C, and 15 ± 2 °C). After storage, the bulbs were grown in a growth chamber at one of three growth temperatures—that is, RT (30 ± 2 °C), 15 ± 2 °C, and 25 ± 2 °C. The results showed that storing bulbs at RT for 12 weeks reduced their quality in terms of fresh weight, diameter, and firmness, whereas storing bulbs at 13 °C or 15 °C retained their quality in terms of fresh weight and firmness. Electron scanning imaging of the starch granules in the bulb scales showed that prior to storage, the leaf base cells were filled with large starch granules of either lenticular shape or spherical shape. After storing for 12 weeks at RT, the starch granules in the bulb scales were sharply reduced in number and were predominantly of the small, spherical form. A growing temperature of 25 °C could stimulate better growth with respect to plant height, flower diameter, bulb diameter, bulb fresh weight, and bulb dry weight, compared with RT (30 °C). A significant interaction between storage and growing temperatures was found for all parameters except for stalk length. A bulb storage temperature of 15 ± 2 °C for 12 weeks combined with a growing temperature of 25 ± 2 °C produced the best results for both flower and bulb production.

Rootstock effects on seed yield and quality in watermelon Abstract This research was conducted to investigate rootstock effects on seed yield and quality in watermelon. The work was conducted in the experimental fields and laboratories of the Department of Horticulture of the University of Cukurova in the 2016 and 2017 growing seasons. Watermelon cv. Crimson sweet (CS) scion was grafted onto three different rootstocks (Cucurbita 'NUN-9075', Lagenaria 'Argentario', and citron watermelon 'PI296341'). Plants were assessed according to their main stem length, main stem diameter, number of nodes, biomass, pollen production and development, fruit yield and quality, and seed yield and quality. NUN-9075/CS and Argentario/CS graft combinations resulted in higher average stem length, plant biomass, fruit yield and quality, seed yield, seed emergence, and germination percentage. There was no significant difference observed between graft combinations in pollen viability, pollen germination, and normal pollen production. No significant difference was observed between graft combinations in accelerated ageing (AA), and the seed germination decreased after AA of 192 h. In the second year (2017), there was higher main stem length, main stem diameter, total fruit yield, seed yield, and number of seeds per fruit compared to the first year (2016). Based on the results of this study, NUN-9075 rootstock performed better than other rootstocks; hence, it is recommended as the best rootstock.

A new interspecific hybrid of Torenia obtained through ovule culture Abstract Torenia is one of the most popular summer bedding plants in Japan. Commercially available hybrids are assumed to be interspecific hybrids derived from T. fournieri, T. concolor, and T. baillonii. Use of new Torenia species is required to produce novel flower types of interspecific hybrids. Three species from Thailand, T. bicolor, T. hirsutissima, and T. siamensis, were selected and crossed with T. fournieri, T. concolor, and T. baillonii. The chromosome number of six Torenia species varied from 2n = 16 to 2n = 34. Mature seeds were obtained from only 3 of 30 reciprocal cross combinations: T. fournieri × T. bicolor, T. fournieri × T. baillonii, and T. bicolor × T. baillonii. Ovule culture was applied to overcome the interspecific crossing barrier of Torenia, ovule culture was applied. Swollen ovules (250) were taken from pods at 10 days after crossing and cultured on MS medium. Progenies were obtained in 14 cross combinations, through ovule culture. This is the first interspecific Torenia hybrid obtained using T. bicolor, T. hirsutissima, and T. siamensis. The hybridity of all the obtained plants was confirmed using PCR–RFLP analysis of rDNA. The obtained hybrids showed intermediate morphological characteristics and pigmentation of floral organs between parents. This study shows that ovule culture is a powerful tool for overcoming the crossing barrier in interspecific crosses in Torenia.

Analysis of flesh color-related carotenoids and development of a CRTISO gene-based DNA marker for prolycopene accumulation in watermelon Abstract Fourteen watermelon cultivars with different fruit flesh colors (red, salmon yellow, orange, and canary yellow) were analyzed for carotenoid contents (prolycopene, lycopene, β-carotene, ζ-carotene, and neoxanthin). Genes encoding the carotenoid biosynthesis enzymes carotenoid isomerase (encoded by CRTISO), which catalyzes the isomerization of prolycopene to lycopene, and β-carotene hydroxylase (CHYB), which catalyzes the conversion of β-carotene to xanthophyll, were also analyzed. High-performance liquid chromatography showed that the salmon yellow and orange flesh accumulated either prolycopene (orange-P flesh) or β-carotene (orange-β flesh), whereas lycopene and neoxanthin were the main carotenoids in the red and canary yellow flesh, respectively. Quantitative real-time polymerase chain reaction indicated that CRTISO and CHYB were mainly expressed during fruit maturation, regardless of the flesh color, and there was no significant association between differential gene expression and flesh color. Importantly, transcript sequencing revealed a non-synonymous single-nucleotide mismatch (T > C1976) in exon 13 of CRTISO between orange-P-fleshed and other cultivars, suggesting CRTISO as a candidate gene for high prolycopene accumulation. However, in β-carotene-accumulating cultivars, there were no mutations in CHYB transcripts. A cleaved amplified polymorphic sequence marker was developed for T > C1976, and its applicability for marker-assisted selection of orange-P flesh was validated in 105 watermelon accessions.

Characterization and utilization of a cytoplasmic male sterility line of Wucai ( Brassica campestris L.) Abstract The novel male sterility line 12-14A of Wucai (Brassica campestris) was generated by backcrossing. In this study, morphological, molecular, and cytological analyses were performed to characterize this line. The phenotypes of flower organs of 12-14A were different from those of its maintainer line 12-14B, as the flowers of 12-14A were completely infertile. Molecular analysis confirmed that the male sterility line 12-14A was classified as the oguCMS type. An analysis of anther development in the CMS line demonstrated that two types of abortion occur simultaneously: pollen mother cell abortion and tetrad-to-mononuclear microspore abortion. In addition, the mature anthers of 12-14A showed typical abortive features, such as appearing dry, shrunken, and scaly. A heterosis test of hybrids from CMS 12-14A and four inbred lines was carried out, and the F1 hybrids exhibited clear heterosis in plant weight, as well as in the protein, soluble sugar, and vitamin C content, suggesting high yields and high quality potential. These results indicate that this novel CMS line may have powerful potential in Wucai hybrid breeding.

Analysis of the changes in medium moisture content according to a crop irrigation strategy and the medium properties for precise moisture content control in rock wool Abstract The substrate moisture content affects crop absorption, microorganisms, oxygen concentration, water stress, and the ultimate evaporation amount. The moisture content in the rhizosphere can be controlled by the amount of water, the frequency of water supply, the time of water supply, and the rate of water supply provided to the crops. The purpose of this study was to investigate the physical properties of a rock wool medium and to investigate the water movement characteristics of the medium according to different watering conditions. To measure the moisture content of the substrate and the drainage amount, load cells were used as weight sensors, and the total irrigation capacity was 99 and 198 mL/min, respectively. The moisture content at each irrigation starting point was set from 30 to 80% of the substrate moisture content at each 5%. The relationship of the starting point of drainage, the 30% drainage rate, the point of the first saturation according to the two different irrigation rates, and the point of moisture content at the start of irrigation showed a sigmoidal relationship. When reviewing the irrigation to the first saturation point, the substrate moisture content got higher as the moisture content at the irrigation start increased. Also, it was shown that the higher the irrigation rate, the higher the saturated moisture content seen in the substrate. The high irrigation rate is useful for the saturation of the substrate, but a large amount of water was needed to adjust the drainage rate. For this reason, we analyzed the irrigation rate under various cultivation conditions.

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com