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Usha Rani Palaniswamy, Richard J. McAvoy, and Bernard B. Bible

Purslane (Portulaca oleracea L.) has been identified as an exceptionally rich source of α-linolenic acid (LNA), an essential fatty acid that is beneficial in reducing the incidence of coronary heart disease and certain cancers. In general, about two thirds of the LNA in terrestrial plants is associated with chloroplasts. A green-leafed unnamed cultivar of purslane and a golden-leafed cultivar `Goldberg' were grown hydroponically in a complete nutrient solution with 14.3 mm nitrogen provided as nitrate (NO3 -) and ammonium (NH4 +) forms to yield NO3 --N: NH4 +-N ratios of 1:0, 0.75:0.25, 0.5:0.5, and 0.25:0.75. Young leaves, harvested 18 days after treatment initiation, were analyzed to determine the fatty acid composition and concentrations, and thylakoid protein and chlorophyll concentrations. Although the leaves of plants grown with a NO3 --N: NH4 +-N ratio of 0.5:0.5 contained 239% and 114% more LNA than plants grown with ratios 1:0 and 0.75:0.25, respectively, they contained only 41% and 26% more chlorophyll. The green-leafed cultivar had higher (39%) chlorophyll concentrations than `Goldberg', but both cultivars had similar LNA concentrations [per g dry weight (DW)]. These results suggest that the LNA concentration in the fatty acid-rich species P. oleracea may not be as closely associated with chlorophyll concentration as reported earlier for other plants. Leaves of plants grown in solutions with 0.25:0.75 NO3 --N: NH4 +-N ratio contained 35% less LNA per g leaf DW than the leaves of plants grown in nutrient solutions with a 0.5:0.5 ratio. Although total DW production was not affected by the NO3 --N: NH 4 +-N ratios in the nutrient solutions, the green-leafed cultivar produced higher fresh weight, leaf area, total DW, and number of shoots than `Goldberg'.

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Usha R. Palaniswamy, Richard J. McAvoy, and Bernard B. Bible

Purslane (Portulaca oleracea L.) is an excellent source of the essential fatty acid α-linolenic acid (LNA) but little is known of the effects of cultural conditions on LNA concentration. Purslane seedlings were grown under an instantaneous photosynthetic photon flux [PPF (400 to 700 nm)] of 299 or 455 μmol·m-2·s-1 for a daily duration of either 8, 12, 16, or 20 hours. Thus, plants were exposed to a daily PPF of 8.6, 12.9, 17.2, or 21.5 mol·m-2·d-1 in the low PPF treatment (299 μmol.m-2.s-1) and 13.1, 19.7, 26.2, or 32.8 mol·m-2·d-1 in the high PPF treatment (455 μmol·m-2·s-1). Plants in all treatments received a 20-hour photoperiod by providing ≈5 μmol·m-2·s-1 from incandescent lamps starting at the end of the photosynthetic light period. At low PPF, purslane grown under a 16 hour PPF duration produced the highest concentrations of total fatty acids (TFA) and LNA per unit leaf dry weight (DW), but at high PPF, concentrations of these compounds were highest under 8 and 12 hour PPF duration. Trend analysis indicated that maximum TFA and LNA concentrations occurred with a daily PPF of 14.1 and 17.2 mol·m-2·d-1, respectively; and in the thylakoids, protein, chlorophyll, and LNA concentrations peaked at a PPF of 21.8, 19.9, and 16.1 mol·m-2·d-1, respectively. LNA as a percentage of TFA was unaffected by treatment. Shoot DW increased with PPF up to the highest PPF exposure of 32.8 mol·m-2·d-1.

Open access

Yuting Zou, Yanan Wang, Mingwei Zhu, Shuxian Li, and Qiuyue Ma

oil content of the seeds, 90.0% of which is unsaturated fatty acids (UFAs). Among the UFAs, α-linolenic acid is the predominant type, accounting for 42.7% of the total content, which is substantially greater than that of traditional oil crops, such as

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Lihang Xie, Lixin Niu, Yanlong Zhang, Min Jin, Duo Ji, and Xiaoxiao Zhang

The effects of different pollen sources on fruit and seed characteristics of Paeonia ostii ‘Feng Dan’ were investigated using analysis of three different pollination treatments and pollen sources from fifteen cultivars in two successive years. The results showed that self-pollination decreased fruit setting, the number of seeds per fruit, seed volume, seed and kernel weights, and the linoleic acid (LA) concentration in the seed oil, but increased the concentration of oleic acid (OA) compared with cross-pollination. Among those pollen donors, P. suffruticosa ‘Yinhong Qiaodui’ produced the highest fruit set (87.5%); the lowest fruit set was obtained with P. suffruticosa ‘Mo Run Jue Lun’ (44.33%). The most seeds per fruit were achieved by P. suffruticosa ‘Mochi Jin Hui’. P. suffruticosa ‘Dahong Baozhu’ produced the largest fruit, which contained larger and heaviest seeds. The oil extraction ratio (26% to 31.6%) and the concentration of three major unsaturated fatty acids (UFAs) in seed oil also significantly differed among pollen sources. The content of OA, LA, and α-linolenic acid (ALA) ranged from 13.82 to 24.79, 12.09 to 21.84, and 23.50 to 38.64 g/100 g crude oil, respectively. Overall, pollen source has clear effects on seed yield and even on fatty acid (FA) composition of seed oil in tree peony.

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Usha Rani Palaniswamy, Richard McAvoy, and Bernard Bible

Omega-3 fatty acids (O3FA) are essential for normal human growth, development, and disease prevention. Purslane (Portulaca oleraceae L.) is an excellent source of the O3FA α-linolenic acid (LNA)—with higher concentrations than any green leafy-vegetable examined to date—and is being considered for cultivation (by USDA-ARS) in an effort to improve the balance of essential fatty acids in the western diet. Twenty-fi ve-day-old seedlings of both a green-leafed and a golden-leafed type of purslane were transplanted into a closed hydroponic system. Nitrogen, at 200 ppm, was provided as NO3 and NH4 forms to yield NO3: NH4 ratios of 1:0, 0.25:0.75, 0.5:0.5, and 0.75:0.25. Treatments were arranged in a randomized complete-block design with five replications. The experiment was repeated. Young, fully expanded leaves were harvested 18 days after treatment initiation, frozen (–60°C), and then analyzed for fatty acids using gas chromatography. Although the two types of purslane did not differ in LNA concentration, the green-leafed purslane produced greater total dry mass than the golden-type. On a leaf dry mass basis, plants grown with a NO3:NH4 ratio of 0.5:0.5 produced 241% and 53% greater LNA than plants grown with NO3:NH4 ratios of 1:0 and 0.75:0.25, respectively. Plants grown with NO3:NH4 ratios of 1:0 and 0.25:0.75 produced similar leaf LNA concentrations. Total dry mass was not affected by the nitrogen treatments.

Open access

Qiuyue Ma, Shushun Li, Jing Wen, Lu Zhu, Kunyuan Yan, Qianzhong Li, Shuxian Li, and Bin Zhang

et al., 2017 ; Liang et al., 2019 ; Wang et al., 2018 ) that contains UFAs, including oleic acid (C18:1), linoleic acid (C18:2), α-linolenic acid (C18:3), and nervonic acid (C24:1) ( Liu et al., 2003 ; Wang et al., 2006 ). In particular, the

Open access

Qin Yang, Yan Fu, Yalan Liu, Tingting Zhang, Shu Peng, and Jie Deng

content of three unsaturated fatty acids: oleic acid, linoleic acid, and α-linolenic acid ( Xie et al., 2017 ). Table 1. Phenotypic characteristics of double-fertilization xenia in some plants. When common corn is pollinated with high-oil corn, the

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Jingyi Lv, Yonghong Ge, Canying Li, Mengyuan Zhang, and Jianrong Li

molecules are ubiquitous lipid-derived signaling compounds in plants, and they play essential roles in plant growth, development, and defense ( Katsir et al., 2008 ). Biosynthesis of JA begins with α-linolenic acid, which is oxygenated by 13-lipoxygenase (13

Open access

Kevin Laskowski and Emily Merewitz

(18:0). The monounsaturated fatty acids were palmitoleic acid (16:1) and oleic acid (18:1), and the polyunsaturated fatty acids were linoleic acid (18:2) and α-linolenic acid (18:3). The fatty acid hexadecadienoic acid (16:2) was not observed in