A number of caladium cultivars (Caladium ×hortulanum), including Miss Muffet and Gingerland, produce rugose leaves. The rugosity on these leaves is an intriguing characteristic, often resulting in an increased ornamental value. This study was conducted to understand the mode of inheritance of this trait and to determine its genetic relationship with other foliar characteristics including leaf shape, main vein color, and leaf spotting in caladiums. Sixteen caladium cultivars/breeding lines were crossed and 20 populations were produced; progeny of these populations were phenotyped for rugose leaf as well as leaf shape, main vein color, and leaf spotting. Results showed that a single locus with two alleles controlled the presence or absence of rugose leaves in these populations. The locus was designated as RLF, with the dominant RLF allele for rugose leaves and the recessive allele rlf for nonrugose (flat) leaves. Rugose cultivars Miss Muffet and Gingerland and breeding line UF-317 possessed the heterozygous genotype RLFrlf. Rugose leaf was inherited independently from leaf shape, but linked with the green main vein allele (V g) at the V locus and the leaf spotting allele (S) at the S locus. Three-point analysis of the segregation of the three linked traits in reciprocal crosses between ‘Miss Muffet’ and nonrugose ‘Candidum’ indicated a genetic linkage map with the gene order of S locus locating between the V and the RLF loci. The information obtained from this study will be useful for developing breeding strategies for producing new caladium cultivars with or without rugose leaves, and can facilitate the understanding of the mode of inheritance for rugose leaves in other aroids and other plants.
Zhe Cao, Shunzhao Sui, Qian Yang and Zhanao Deng
Joyce W. Ngure, Chunyan Cheng, Shuqiong Yang, Qunfeng Lou, Ji Li, Chuntao Qian, Jie Chen and Jinfeng Chen
Cucumber (Cucumis sativus) seed oil has the potential for use as an edible oil and as a pharmaceutical, cosmetic, insecticidal, and industrial product. In this study, we investigated, for the first time, the effect of cultivar and season on seed number, oil content, and fatty acid profiles as well as their proportions in different cucumber cultivars. We examined the effects of spring and autumn seasons on seed oil content and fatty acid composition in 46 cucumber cultivars and one wild species of cucumber (C. anguria) grown in greenhouse experiments in 2013 and 2014. Seed oil was determined using the Soxhlet method and fatty acids using the gas chromatography-mass spectrometry method. Seed oil content in the cucumber seeds ranged from 41.07% in ‘Hazerd’ to 29.24% in ‘Lubao’ while C. anguria had 23.3%. Fatty acids detected were linoleic (C18:2), palmitic (C16:0), oleic (C18:1), stearic (C18:0), linolenic (C18:3), behenic (C22:0), arachidic C20:0), lignoceric (C24:0), eicosenoic (C20:1), palmitoleic (C16:1), and myristic (C14:0), among other unidentified fatty acids. The results showed significant effects of cultivar genotype, growing season, and interactions on the variables examined. The content of seed oil and fatty acids differed significantly among the cultivar genotypes. Spring-grown cucumbers had higher quantities of oil than the autumn-grown cucumbers. The content of fatty acids (mainly palmitic, palmitoleic, stearic, oleic, eicosenoic, and lignoceric) also was higher in spring. In autumn there were more seeds, and higher linoleic, linolenic, and other unspecified fatty acids. The higher the oleic acid content the lower was the linoleic acid indicating a strong negative relationship in these two fatty acids. The higher the seed oil content the higher was linoleic and oleic indicating a positive relationship between the seed oil and the two fatty acids. Results of this study provide important information applicable in improving management and production of cucumber seed oil especially considering its versatility in uses. Furthermore, the wide range of fatty acids found in the studied cucumber cultivars could be used in the production of novel industrial oils through genetic engineering.
Yong Zhang, Chunxia Fu, Yujing Yan, Yan’an Wang, Ming Li, Meixiang Chen, Jianping Qian, Xinting Yang and Shuhan Cheng
This research was initiated to determine the response of apple (Malus ×domestica) fruit quality to sprays of zinc sulfate (ZnSO4) and sugar alcohol zinc. Two apple cultivars Fuji and Gala were evaluated, the leaf zinc (Zn) concentration of which were about 14.3 mg·kg−1 dry weight without Zn deficiency symptoms. The trees were sprayed with ZnSO4 and sugar alcohol zinc separately during four different developmental stages: 2 weeks before budbreak (P1), 3 weeks after bloom (P2), the termination of spring shoot growth (P3), and 4 weeks before harvest (P4). The fruit was harvested at maturity and analyzed for fruit quality and fruit Zn concentration. Zinc sprays during the four different developmental stages increased Zn concentration of peeled and washed fruit at harvest, without phytotoxicity. The treatments at stages P2 and P4 increased average fruit weight of ‘Gala’ and ‘Fuji’, respectively. The treatments at stages P1 and P4 increased the fruit firmness of ‘Gala’, while the treatments at stages P1 and P2 increased the fruit firmness of ‘Fuji’. The treatments at stages P1, P2, and P4 increased the soluble sugar and vitamin C of ‘Gala’ fruit, while the treatments at all the stages increased the soluble sugar and vitamin C of ‘Fuji’. And the effects of sugar alcohol zinc were equal and more pronounced than those of ZnSO4. Thus, Zn sprays at critical periods can improve fruit quality of apple trees, which show no Zn deficiency symptoms with leaf Zn concentration less than 15 mg·kg−1 dry weight.