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Ou L.J.,University of South China | Ou L.J.,Huaihua University | Zou X.X.,University of South China | Zou X.X.,Vegetable Institution of Hunan Academy of Agricultural Science
Photosynthetica | Year: 2012

The aim of the study was to investigate the genetic distances and their relationships among pepper species using photosynthetic features under different stresses and genetic variability. The photosynthetic features under drought, waterlogging and low-temperature stresses, rDNA internal transcribed spacer (ITS) sequences of nuclear genome and trnH-psbA sequence of chloroplast genome of 25 varieties from 5 pepper species Capsicum annuum L. (CA), Capsicum baccatum L. (CB), Capsicum chinense Jacquin. (CC), Capsicum frutescens L. (CF) and Capsicum pubescens Ruiz & Pavon (CP) were analyzed and used to construct the dendrograms. The results showed the photosynthetic rate of different pepper species could be greatly but differentially decreased by stresses. For example, CB and CF had the smallest and the highest decrease to drought, CC had the highest decrease to waterlogging, and CP had the smallest decrease to low temperature. The ITS sequences of 25 pepper varieties are 591-619 bp in length and have GC% between 51.1% and 64.5%. Their trnH-psbA sequences are 537-558 bp in length and have GC% between 27.2% and 28.5%. The cluster analysis of the five pepper species based on the changes in P N under stresses is similar to that based on genetic variability, that is, CP clusters with CB, and CC clusters with CA after first clusters with CF. In addition, the clustering methods based on the photosynthetic stress responses and genetic variability are unable to completely distinguish pepper varieties within the same species. The results indicate that similarly to genetic variability, changes in P N under stresses (specifically the stress corresponding to the climate of plant's original habitat) could be used to identify genetic distance of pepper species. © 2012 Springer Science+Business Media B.V. Source


Lijun O.,University of South China | Lijun O.,Huaihua University | Lijun O.,Vegetable Institution of Hunan Academy of Agricultural Science | Xuexiao Z.,University of South China | Xuexiao Z.,Vegetable Institution of Hunan Academy of Agricultural Science
African Journal of Biotechnology | Year: 2012

This paper studied the genetic diversity of five cultivated pepper species using inter simple sequence repeat (ISSR) analysis. The amplicons of 13 out of 15 designed primers were stable polymorphic and therefore were used as genetic biomarkers. 135 total clear bands were obtained, of which 102 were polymorphic bands with an average polymorphism rate of 75%. The cultivated species Capsicum annuum L. had less specific genotype bands compared with two wildtype species; its Nei's gene diversity index, Shannon's diversity index and genetic differentiation index were 0.21, 0.33 and 0.8306, respectively. The genetic variations of these five species were mainly interspecifically rather than intraspecifically. Cluster analysis showed that they belonged to different branches: C. annuum L., Capsicum chinense Jacquin. and Capsicum frutescens L. were in one cluster, whereas Capsicum baccatum L. and Capsicum pubescens Ruiz and Pavon were in another cluster. C. annuum L. had the least genetic polymorphism. Our results suggested that ISSR markers are valid tags in the studies on pepper genetic diversity and that cultivated species identification and gene exchange between cultivated and wild species should be strengthened in pepper breeding to improve heterosis. © 2012 Academic Journals. Source


Ou L.,Huaihua University | Ou L.,Key Laboratory of Hunan Province for Study and Utilization of Ethnic Medicinal Plant Resources | Ou L.,Vegetable Institution of Hunan Academy of Agricultural Science | Ou L.,Key Laboratory of Hunan Higher Education for Hunan Western Medicinal Plant and Ethnobotany | And 2 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012

Increased human activities have had a significant impact on the global climate. Abnormal changes, such as drought stress caused by long-term un-rain, can affect plant growth and development. Pepper (Solanaceae), originally planted in tropical areas of South America, not only has medicinal value it has the highest vitamin C content of all vegetables. The International Board for Plant Cenetic Resources (IBPCR) has classified pepper species into five species; Capsicum annuum L. (CA), Capsicum baccatum L. (CB), Capsicum chínense Jacquin. (CC), Capsicum frutescens L. (CF), Capsicum pubescens Ruiz and Pavon (CP). CA is the most differentiated, widely cultivated species being the focus of pepper breeding worldwide. Screening of resistant germplasms is one of the most important measures against abnormal climate changes. Pot experiments were employed to determine the photosynthetic response and associated physiological characters, such as superoxide dismutase (SOD) and glutathione reductase (CR) activities, root activity and adventitious root number, of five domesticated and one wild pepper species (C baccatum var. baccatum (CBY)) to drought stress. The photosynthetic pigment content decreased the net photosynthetic rate (PN) of all tested peppers continued to decline on the first day of regular irrigation, then started to increase on the second day, and almost recovered to normal levels by the seventh day. Non-photochemical quenching (q N), water use efficiency (WUE), and root activity had increased dramatically, the SOD and CR activities of all the pepper species first increased, being highest on day 4, and subsequently decreased. The number of adventitious roots slightly increased in all peppers, suggesting that pepper has a stronger resistance to drought stress. The results also show that changes in the above parameters vary in different species. CB had smaller decreases in photosynthetic pigment content, PN and stomatal conductance (gs,), and greater increases in qN, WUE, SOD and CR activities and root activity, indicating that CB has the strongest resistance to drought stress. CC and CF showed bigger decreases in photosynthetic pigment content, PN and gs with smaller increases in qN, WUE, SOD, and CR activities and root activity, indicating they have weaker drought stress resistance. In addition, the wild pepper, C. baccatum var. baccatum (CBY), had the smallest decrease in photosynthetic pigment content, PN and gs with the greatest increases in qN, WUE, SOD, and CR activities, and root activity. This indicates that CBY has better resistance to adverse environments than all tested species, which is perhaps caused by the loss of stress resistance genes during the process of domestication. Our study found that, of the species tested, the ability to resist drought stress is strongest in wild pepper CBY. Of the five species tested, CB had the highest photosynthetic rate and strongest drought resistance capability. In conclusion, we suggest that crossbreeding of domestic and wild pepper species be considered for commercial breeding. Such a measure will not only expand the genetic pool, increasing genetic distance and eventually increasing production; it will also to introduce elite stress tolerance genes improving each species' ability to resist adverse environments. Source


Lijun O.,Vegetable Institution of Hunan Academy of Agricultural Science | Lijun O.,Huaihua University | Zhuqing Z.,Vegetable Institution of Hunan Academy of Agricultural Science | Xiongze D.,Vegetable Institution of Hunan Academy of Agricultural Science | Xuexiao Z.,Vegetable Institution of Hunan Academy of Agricultural Science
Acta Physiologiae Plantarum | Year: 2012

This study compared the sequence variations and expressions of 12 chloroplastic and 8 mitochondrial genes in three pepper (Capsicum annuum L.) cytoplasmic male sterile (CMS) lines, their maintainers and two control cultivars. The results showed that the three CMS lines were highly similar in chloroplastic and mitochondrial fragment sequences, with average similarities of 96. 81 and 98. 73 %, respectively, and their chloroplastic trnH-psbA intergenic spacer, photosystem II 47 kDa protein (psbB) genes, mitochondrial apocytochrome b (cob) and RNAD fragments have 1, 9, 8 and 7 distinct sites from the maintainer lines, respectively, and could be used as informative sites to distinguish CMS lines from the maintainer lines. Meanwhile, the expressions of mitochondrial cob, RNAD and pvs in the reproductive organs (flowers) of CMS lines are different from those of the maintainer lines, but their expressions in the vegetative organs (roots and leaves) are similar. The results indicate that cytoplasmic DNA polymorphisms are rare in CMS lines, and mitochondrial cob, RNAD and pvs genes are closely related to pollen abortion. © 2012 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków. Source


Ou L.-J.,Vegetable Institution of Hunan Academy of Agricultural Science | Ou L.-J.,Huaihua University | Zhang Z.-Q.,Vegetable Institution of Hunan Academy of Agricultural Science | Dai X.-Z.,Vegetable Institution of Hunan Academy of Agricultural Science | Zou X.-X.,Vegetable Institution of Hunan Academy of Agricultural Science
PLoS ONE | Year: 2013

Huai Zi (HZ) is a new purple mutant of green pepper (PI 631133) that is obtained from the United States Department of Agriculture. The net photosynthetic rate (PN), chlorophyll fluorescence parameters, antioxidant substances, antioxidant enzymes, photosystem 1 (PS1) and PS2 activities were studied through methyl viologen (MV) treatment. The results showed that the PN, actual photochemical efficiency of PS2 (ΦPS2), photochemical quenching coefficient (qP), PS1 and PS2 activities in HZ were lower than those in green pepper. HZ had a stronger ability to eliminate reactive oxygen species(O2 •-) and accumulated less malondialdehyde (MDA) (a membrane lipid peroxidation product) than did green pepper, and had a higher content of antioxidants and antioxidant enzyme activity. This suggests that the lower light energy absorption and higher thermal dissipation and antioxidant activity of HZ contributed to a more stable PS2 photosynthetic capacity, which resulted in photooxidation tolerance. Hence, our study strongly suggests that pepper hybrids can achieve a modest ratio of chlorophyll and anthocyanin content, high PN and resistance to photooxidation, improving yield and resistance to adverse environments. © 2013 Ou et al. Source

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