Combining Ability Analyses of Net Photosynthesis Rate in Pepper (Capsicum annuum L.)

In perspective of breeding high-yield hybrid pepper varieties, combining ability analysis of net photosynthesis rate at different phases of flowering and fruit setting in pepper was made with 15 cross combinations from 6 parents by （1/2） n （n- 1） diallel crosses. There are relatively large differences not only in general combining ability （GCA） effect among different parents and at different phases of flowering and fruit setting, but also in specific combining ability （SCA） effect among different hybrids. There are relatively large GCA effects in late parents but relatively less GCA effects in early parents. No obvious laws have been found in the relationship between SCA effects and maturity of hybrids. Variances of SCA are larger than those of GCA. Heritability is less but influence of environment is larger. Correlation analysis of combining ability between net photosynthesis rate and agronomic character or resistances to main diseases has showed that correlation coefficients of GCA are relatively large at the medium phase and the late phase of flowering and fruit setting. Net photosynthesis rate is more relative to leaf characters and fruit characters. Correlation coefficients of SCA are relatively large at the early phase and the late phase of flowering and fruit setting. Net photosynthesis rate is more relative to leaf characters and plant characters at the early phase but to plant characters and fruit characters at the late phase. Correlation coefficients of SCA between net photosynthesis rate and resistances to main diseases are larger than those of GCA. The combining abilities of net photosynthesis rate at different phases of flowering and fruit setting are positively correlated with those of yield per plant. The combining ability is an important parameter of breeding of high photosynthesis hybrid pepper varieties.

Mutation in the Agrobacterium his I gene enhances transient expression in pepper

Agrobacterium-mediated plant transformation is widely used in plant genetic engineering.However,its efficiency is limited by plant immunity against Agrobacterium.Chili pepper(Capsicum annuum L.)is an important vegetable that is recalcitrant to Agrobacterium-mediated transformation.In this work,Agrobacterium was found to induce a strong immune response in pepper,which might be the reason for T-DNA being difficult to express in pepper.An Agrobacterium mutant screen was conducted and a point mutation in the hisI gene was identified due to a weak immune response and enhanced transient expression mediated by this Agrobacterium mutant in pepper leaves.Further genetic analysis revealed that histidine biosynthesis deficiency caused by mutations in many genes of this pathway led to reduced pepper cell death,presumably due to reduced bacterial growth.However,mutation analysis of threonine and tryptophan biosynthesis genes showed that the biosynthesis of different amino acids may play different roles in Agrobacterium growth and stimulating the pepper immune response.The possible application of Agrobacterium amino acid biosynthesis mutations in plant biology was discussed.

Combining Transcriptomics and Metabolomics to Uncover the Effects of High-Energy Lithium-Ion Beam Irradiation on Capsicum annuum L.

Hot pepper(Capsicum annuum L.)is consumed as one of the oldest domesticated crops all over the world.Although mutation breeding using radiation has been performed in hot peppers,little is known about the comparative analysis of mutagenic effects at the molecular level by ion beam irradiation.To comprehend the response mechanism of hot pepper to the ion beam,we used a mutant with favorable economic characteristics induced by lithium-ion beam irradiation to investigate the biological effects.The results indicated that the lithium-ion beam had a positive effect on important agronomic traits,particularly yield unit,but had a negligible effect on the photosynthetic rate of hot pepper,with a specific influence on chlorophyll b rather than chlorophyll a.By RNA-Seq analysis,671 up-regulated and 376 down-regulated genes were identified as differentially expressed genes(DEGs)between irradiated and unirradiated hot pepper.Based on GO and KEGG network analysis,the auxin metabolic process was the common pathway in these two networks.A total of 118 potential reactive oxygen species(ROS)scavenging genes and 262 signal transduction genes were identified,suggesting a balance between antioxidant enzymes and enhanced ROS transduction.The amounts of 15 metabolite,involved in GABA pathways,secondary metabolism,carbohydrate metabolism,shikimate pathways,TCA cycles,nitrogen metabolism,glycerol metabolism and acetate pathways,were significantly changed in the ion beam irradiated sample.These results highlighted that the enriched pathways could play important roles in response to ion beam irradiation in hot pepper plants.In summary,these data provide valuable information for future research on ion beam irradiation and genomic studies in hot pepper.

Diallel Crossing Analyses of Resistance to Main Diseases in Pepper(Capsicum annuum L.)

Fifteen capsicum combinations were made with 6 parents by （1/2）n（n-1） diallel crossing. Genetic parameters in the resistance to TMV, CMV, phytophthora blight, bacterial spot of these combinations were studied by Hayman. The results indicated that the resistance to TMV, CMV and bacterial spot conformed genetically to the “additive-dominant” model but the resistance to phytophthora blight did not and significant epistatic dominance effect existed in it. F1 hybrid＇s resistance to CMV was controlled by homozygous dominant gene （s）, but resistance to bacterial spot by heterozygous one （s）. There were little, or no sum of dominant effect and genomes controlling the dominant expression of F1 hybrids in its phytophthora blight resistance.

Organ Abscission in Plants: With Special Emphasis on Bell Pepper

Bell pepper(Capsicum annuum L.),along with potato and tomato,is one of the three most cultivated vegetables in the world.Bell pepper is worldwide accepted due to its characteristics of color,smell,flavor,and texture.Bell pepper is also considered a nutritious food due to its vitamin and antioxidant contents.In Mexico,bell pepper production has a high value because it is grown for the international markets,particularly the United States of America.Nevertheless,the abscission offlowers and fruits is a factor that limits the yield,hinders the planning of activities,and causes a variation in the prices of peppers.Due to the importance of this process,in this work we did a bibliometric analysis and literature review of scientific advances for the understanding of the abscission pro-cess in plants,and in particular for the bell pepper.Finally,we introduce new perspectives that would help direct future research about organ abscission in plants.Likewise,the lack of research that would further clarify abscis-sion process in the bell pepper plant is discussed.

AFLP Analysis of Mitochondrial DNA from a Cytoplasmic Male Sterility Line and its Maintainer in Pepper (Capsicum annuum L.)

Cytoplasmic male sterility (CMS) is a maternally inherited trait characterized by the inability of a plant to produce functional pollen, which is widespread among higher plants. CMS system is a valuable tool for plant

Investigation of the Effects of Radio Frequency Water Treatment on Some Characteristics of Growth in Pepper (<i>Capsicum annuum</i>) Plants

The aim of the present study was to investigate the effect of electromagnetic radio frequency treatment of water on the growth of pepper (Capsicum annuum) plants. For this experiment, one hundred one-week old plants were divided into two groups. The first group of plants was watered with water subjected to radio frequency electromagnetic radiation from an internet router for one hour a day, while the other group was watered with tap water (control). The overall results showed changes of growth characters of plant watered with electromagnetic water. The length of pepper plants is significantly affected by the treated water, where the length of shoot was lower in plants grown under the effect of treated water (22.43 ± 7.17 cm) than those grown without treated water (28.11 ± 8.57 cm). The results revealed that the stem diameter of control plants (1.74 ± 0.39 cm) was significantly higher than that of the treated plants (1.66 ± 0.35 cm). In addition, the root length was lower in plants grown under the effect of treated water than those grown without treated water. Pepper plants watered with electromagnetic treated water exhibited marked decreases in health index, fresh and dry weight, relative water content, number of flowers and fruits/plant as well as number of seeds/fruit. In addition, the current experiment showed a significant decrease in the number of leaves, branch and flower per plant when watered with electromagnetic treated water. The results revealed that the first flowering time for plants in treated group was remarkably decelerated when compared to other plants in control group.

Influence of Red Pepper (<i>Capsicum annuum</i>) Addition on Bioenergy Production in Microbial Fuel Cells

The current study was performed to evaluate the beneficial effect in the power output of microbial fuel cells (MFCs) through supplementation of dried red pepper (Capsicum annuum) powder into the anodic chamber. Mediator-less H-type MFCs were set up where the anode chamber contained rumen microorganisms as inocula on cellulose (Avicel) and the cathode chamber of phosphate buffered saline (pH 7.4), both separated by cation exchange membrane. Electrical power generation in MFC was monitored daily over a 10-day period and the accumulated amounts and components of gaseous byproducts were measured at the end of 10 d operation of MFC. For both groups of MFCs with red pepper and the control, the head space gases collected were methane and CO2, and its volume and composition were similar between treatments. Methane and CO2 produced for 10 d operation were 210.7 and 106.5 mL, respectively, in MFC. The addition of red pepper powder caused an average power density to increase from 24.0 mW/m2 to 39.6 mW/m2 (P 2 for control and bellflower, respectively. This study provides the strong evidence that red pepper (Capsicum annuum) supplementation might modify the anaerobic fermentation characteristics of rumen microorganisms in anode chamber and improve the cellulosic bioenergy production in MFC.

Purification and Biochemical Characterization of a Protease Inhibitor Ⅱ Family from Jalapeno Pepper(Capsicum annuum L.)

Capsicum annuum L. was initially domesticated in Mexico and northern Central America, and represented an ancient Neotropical plant food complex. The purpose of this paper is to report the isolation and purification of a novo-member of a protease inhibitor from jalape&ntildeo pepper (Capsicum annuum L.) (PIJP). The molecular weight of PIJP inhibitor is 5.95 kDa with 56 amino acids and 6 Cys residues with high inhibitory activity to trypsin with a Ki value of 95 nM. This inhibitor according to the alignment with homologous from NCBI and Pfam databases is a member of proteinase inhibitors II. It is worthwhile to mention a major compositional difference between the proteinase inhibitor II families which have 8 Cys residues. PIJP is the first purified proteinase inhibitor, member of this family with only 6 Cys residues.

Construction of Mutant Population and Analysis of Dwarf Mutants in "6421"(Capsicum annuum L.)through EMS Mutagenesis

[Objective] The aim was to improve the genetic property of peppers, the mutant population of Capsicum annuum L cultivar ＂6421＂ was constructed. [Method] The seeds of ＂6421＂ were treated with 0.2% to 1.2% ethyl methane sulfonate to identified LD50, and then 10 000 LD^o of treated seeds were sowed to construct mutant population. The agronomic characters and genetic regularity of dwarf mutants in M4 generation were analyzed. [Result] Our results showed that GR and SSR were 45.2% and 40.2% respectively at 1.0% EMS, close to LD50, with GI （17.6） and seed Ⅵ （19.7） being half of that of control; 562 M4 mutants were identified in 2015, and the mutation could be characterized according 11 major categories and 32 subcategories; Simultaneously, we found that plant height, plant width, diameter of mainstem, length of main-stem, the number of main-stem nodes and branch of lines E29, E58, E142 and E312 were all significantly different from that of the control. The mutation of lines E29, E58 and E312 was all controlled by a single recessive gene. [Conclusionl The study first created a pepper mutant population, which provides not only the germplasm resources for further breeding but also direct and effective materials for genomic study of the pepper.

五彩椒(Capsicum annuum L.)的组织培养研究

以抗寒性较强的五彩樱桃椒为试验材料,对观赏椒的组织培养进行了研究。试验表明,最佳外植体为茎尖,茎尖的最佳消毒时间为3min;最佳诱导培养基为MS+6-BA5mg·L-1+NAA1mg·L-1;最佳分化培养基为MS+6-BA5mg·L-1+NAA0.1mg·L-1,最佳生根培养基为1/2MS+IBA0.25mg·L-1。

Effect of Different Culture Conditions on Sporulation Quantity of Phytophthora capsici in Capsicum annuum L. var. dactylus M. in Xunhua

[Objective] The paper was to explore the effect of different culture conditions on sporulation quantity of Phytophthora capsici in Capsicum annuum L.var.dactylus M.in Xunhua.[Method] The effects of light hours,pH,medium and temperature on sporulation quantity during isolation and culture process of P.capsici were studied.[Result] The sporulation quantity of P.capsici under the conditions of 24 h/day light,pH 7.0,potato medium（PSA） and 30 ℃ was the largest,and pH,basal medium and temperature had greater impact on sporulation quantity.[Conclusion]The study laid foundation for the study on natural incidence condition of C.annuum in Xunhua.

Residue Dynamics of Mancozeb in Capsicum annuum Linn and Soil

[ Objective ] The paper was to study the residue dynamics of mancozeb in Capsicum annuum Linn and soil. [ Method ] Field spraying test and indoor analysis were carried out in three places of Changsha, Guangzhou and Beijing City during 2008 -2009 to study the digestion dynamics and the final residue of man- cozeb in C. annuum and soil, and gas chromatography was used for quantitative analysis. [ Result]The average recovery rates of mancozeb in C. annuum and soil were 86.59%-93.03% and 92.57%-95.14%, respectively. Mancozeb had rapid digestion in C. annuum and soft with the half-life of 2.29 -4.65 and 4.01 - 4.65 d, respectively. When metalaxyl-M,mancozeb water dispersible granule was sprayed in C. annuum according to the recommend dose （ spraying for no more than three times with the spraying interval of 5 d）, the final residue of maneozeb in C. annuum collected in the third day after the last spraying was less than 2 mg/kg.

膜透气性参数对朝天椒(Capsicum annuum var.conoides)自发气调包装冷藏效果的影响

以红熟期朝天椒为材料,结合自发气调包装(modified atmosphere packaging,MAP)和(9±0. 5)℃低温贮藏技术,研究了不同透气性参数的聚乙烯包装膜对朝天椒低温贮藏保鲜效果的影响。结果表明,MAP处理可有效降低朝天椒贮藏过程中的失重率,包装膜透气性参数对包装后朝天椒的贮藏品质影响具有明显差异。MAP处理中除E处理[包装膜O2和CO2透过率分别为1 865 cm3/(m2·24 h·0.1 MPa)和7 214 cm3/(m2·24 h·0.1 MPa)]加速了朝天椒的腐烂外,其他4个处理均能不同程度抑制朝天椒贮藏过程中组织相对电导率的升高,减少腐烂的发生,延缓外观品质的劣变。其中,C处理[包装膜O2和CO2透过率分别为8 087 cm3/(m2·24 h·0. 1 MPa)和31 520 cm3/(m2·24 h·0. 1 MPa)]在贮藏30 d时朝天椒商品性最好。

气孔在辣椒(Capsicum annuum L.)子叶和下胚轴上的动态变化

以辣椒幼苗(Capsicum annuum L.)为材料,研究了辣椒生长发育过程中子叶的上、下表皮和下胚轴上、下端1 cm处的气孔密度及表皮细胞密度的动态变化。结果表明:(1)辣椒的气孔由肾形保卫细胞组成,无副卫细胞;子叶的表皮细胞呈无规则形,下胚轴的表皮细胞呈长方形或椭圆形;(2)辣椒子叶上、下表皮的气孔密度和表皮细胞密度分别在辣椒种子出芽后第6天和第3天达到最大,之后随子叶的生长逐渐减小,下表皮的气孔密度和表皮细胞密度明显大于上表皮的;(3)辣椒下胚轴上、下端1 cm处的气孔密度随下胚轴的生长变化不明显,但是表皮细胞密度随下胚轴的生长逐渐减小,下胚轴上端的气孔密度和表皮细胞密度明显的大于下胚轴下端的。

基于加权关联网络分析的辣椒(Capsicum annuum L.)果实颜色转变相关基因的鉴定

辣椒属于茄科(Solanaceae)辣椒属(Capsicum L.)一年生或多年生植物,其播种面积和产值在中国均居蔬菜首位。果色是辣椒众多经济性状中最直观的性状之一,直接影响人们的购买选择。辣椒果色受多种因素调控,相关色素生物合成的分子调控还需进一步解析。本研究以果实发育过程中呈现5种颜色的辣椒种质HNCA0076为实验材料,进行了生理检测、转录组测序以及WGCNA分析。在果实5个不同颜色时期,叶绿素含量变化较大,类胡萝卜素含量整体呈现递增趋势,类黄酮含量无明显变化,花色苷含量在紫色果期后逐渐降低,橙色果期后又逐渐升高。RNA测序数据质量满足进一步分析要求。4个转色期的上调(下调)表达基因数分别为826(276)、390(588)、1248(1800)和1528(2485),随着果实的逐步发育,相邻比较组合中的差异基因的数量逐渐增加。差异表达基因经GO富集分析,主要集中在分子功能中的四吡咯结合、血红素结合、转移酶活性、氧化还原酶活性、铁离子结合和水解酶活性等过程;KEGG富集分析主要富集在类胡萝卜素生物合成、类黄酮生物合成和淀粉、蔗糖代谢等信号通路,其中类胡萝卜素代谢途径的3个基因在紫色时期向黄色时期的转变过程中表达上调,类黄酮代谢途径的11个基因在黄色时期向红色时期的转变过程中表达下调。4个对比组合差异基因分别注释到8877、8736、8689、8573个转录因子,共同注释到8049个转录因子,包括AP2、F-box、MYB和UDPGT等类型。利用非冗余的差异表达基因进行了加权关联网络分析,关联到4个与叶绿素、类胡萝卜素、花色苷、类黄酮含量相关的模块,进一步分析表明p450(LOC107859314)、Pkinase(LOC107839192、LOC107875415)、F-box(LOC107863894)和zf-MYND(LOC107852593)等29个转录因子可能参与辣椒果实转色的调控。本研究为进一步探索辣椒果实色素形成过程中的关键调控因子以及分析相关色素生物合成的调控提供了重要数据。

Responses of the Anthocyanin and Osmolyte Contents of the Capsicum annuum Cultivars Planted in Wenshan Prefecture of Yunnan Province to the Drought Stress Simulated by PEG-6000

[Objective] The aim of this study was to compare the drought resistance difference of the main Capsicum annuum cultivars planted in Wenshan Prefecture of Yunnan Province. [Method] The total anthocyanin, soluble sugar, soluble protein and free proline contents of the leaves of the five main C. annuum cultivars planted in Wenshan Prefecture, i.e., ZSZ75-1, ZSZ49-1-1, 12WS-18-1, 12ZH01 and ZS130, under the drought stress simulated by PEG-6000 were studied by using spectrophotometry, and the total osmoregulation abilities of the leaves were evaluated by using subordinate function. [Result] Under the drought stress simulated by PEG-6000, the total anthocyanin contents of the veins, mesophylls and whole leaves of the five cultivars were all as： ZSZ75-1〉ZSZ49-1-1〉12WS-18-1〉12ZH01〉ZS130, the soluble sugar contents as： 12ZH01 〉12WS-18-1 〉ZS130〉ZSZ49-1-1 〉ZSZ75-1, the soluble protein contents as： ZSZ75-1〉12ZH01〉ZSZ49-1-1〉12WS-18-1〉ZS130, and the free proline contents as： ZS130〉ZSZ75-1 〉12WS-18-1 〉ZSZ49-1-1 〉12ZH01. Furthermore, the differences among the total anthocyanin contents of the veins, mesophylls and whole leaves of the five cultivars all reached the extremely significant levels, whereas the differences among the contents of the soluble sugar, soluble protein and free proline did not reach the significant levels, the correlation degrees among the contents of the total anthocyanin, soluble sugar, soluble protein and free proline of different cultivars were also inconsistent, and the total osmoregulation abilities of the five cultivar leaves were as： ZSZ75-1 〉7SZ49-1-1 〉12WS-18-1 〉ZS130〉12ZH01. [Conclusion] The anthocyanin accumulation in the specific organs of the five C. annuum cultivars in Wenshan Prefecture is beneficial to the strengthening of the leaf osmoregulation abilities under drought stress, favoring the drought tolerance of the cultivars.

Effects of Chlorine Dioxide Gas on Postharvest Physiology and Storage Quality of Green Bell Pepper (Capsicum frutescens L.var.Longrum)

The effects of treatment of chlorine dioxide （C1Oz） gas on postharvest physiology and preservation quality of green bell peppers were studied. Green bell peppers were collected in bags and treated with 0, 5, 10, 20, and 50 mg L^-1 ClO2 gas at 10±0.5℃ for over 40 d, and the changes in postharvest physiology and preservation quality of the peppers were evaluated during the storage. The inhibition of rot of the peppers was observed for all the tested ClO2 gas treatments. The rot rates of the treated samples were 50% lesser than those of the control after day 40 of storage. The highest inhibitory effect was obtained after 50 mg L^-1 ClO2 gas treatment, where the peppers did not decay until day 30 and showed only one-fourth of the rot rate of the control at day 40 of storage. The respiratory activity of the peppers was significantly （P〈0.05） inhibited by 20 and 50 mg L^-1 ClO2 treatments, whereas no significant effects on respiratory activity were observed with 5 and 10 mg L^-1 ClO2 treatments （P〉0.05）. Except for 50 mg L^-1 ClO2, malondialdenyde （MDA） contents in the peppers treated with 5, 10, or 20 mg L^-1 ClO2 were not significantly （P〉0.05） different from those in the control. Degradation of chlorophyll in the peppers was delayed by 5 mg L-1ClO2, but promoted by 10, 20, or 50 mg L^-1 ClO2. The vitamin C content, titratable acidity, and total soluble solids of the peppers treated by all the tested ClO2 gas did not significantly change during the storage. The results suggested that ClO2 gas treatment effectively delayed the postharvest physiological transformation of green peppers, inhibited decay and respiration, maintained some nutritional and sensory quality, and retarded MDA accumulation.

Cloning and characterization of CaGID1s and CaGAI in Capsicum annuum L.

Fruit set and development are affected by many phytohormones, including gibberellin. Little is known regarding molecular mechanism underlying gibberellin mediated fruit set and development especially in Capsicum. Three gibberellin recep- tors, CaGIDlb.1, CaGIDlb.2 and CaGIDlc, and a DELLA protein, CaGAI, have been identified in Capsicum annuum L. During the fruit development, the expression level of CaGIDlc was low, and the expression fold change is mild. However, CaGIDlb. 1 and CaGIDlb.2 were relatively higher and more acute, which indicates that CaGIDlb. 1 and CaGID1b.2 may play an important role in fruit pericarp, placenta and seed. Ectopic expressions of CaGIDlb. 1, CaGIDlb.2 and CaGIDlc in Arabidopsis double mutant gidla gidlc increased plant height, among which CaGIDlb.2 had the most significant effect; CaGAI reduced plant height in double mutant rga-24/gai-t6, having a similar function to AtGID1 and AtGAI in stem elon- gation. Yeast two-hybrid （Y2H） and bimolecular fluorescence complementation （BiFC） assays indicated that CaGIDlb.1 and CaGID1 b.2 interact with CaGAI in a GA-dependent manner, while CaGIDlc interacts with CaGAI in a GA-independent manner. Our study reveals the key elements during gibberellin signaling in Capsicum and supports the critical importance of gibberellin for Capsicum fruit set and development.

Identification and Characterization of a LEA-like Gene, CaMF5,Specifically Expressed in the Anthers of Male-fertile Capsicum annuum

To improve the understanding of molecular mechanisms of anther and/or pollen development in Chili pepper, in the present study, fulllength cDNA and DNA sequences of the pollen development-related gene CaMF5 were obtained from the anthers of a Capsicum annuum nuclear male-fertile line. Sequence analysis indicated that the full length of CaMF5 was 747 bp, containing a maximum opening reading frame of 447 bp.Amino acid sequence alignment and phylogenetic analysis revealed that CaMF5 shared approximately 37%–77% homology with a series of uncharacterized or hypothetical proteins and late embryogenesis abundant(LEA) proteins from other plants. However, no LEA structural domain was detected in CaMF5, which indicated that it might be a new type of LEA gene. CaMF5 was only expressed in flower buds at stages 7 and 8 and in open flowers of the male-fertile line, whereas it exhibited no expression in any examined organs of the male-sterile line. In addition, CaMF5 showed the highest transcript abundance in the anthers of the male-fertile line, with no expression being detected in any other examined organs, such as the sepals, petals, pistils, roots, stems, or leaves. Taken together, our results suggest that CaMF5 is an anther-specific gene that might encode a new type of LEA protein related to anther and/or pollen development in C. annuum.