Effect of Different Sowing Dates on Disease Initiation and Development of Roselle (<i>Hibiscus sabdariffa</i>L.) Leaf Spot Disease Caused by <i>Coniella musaiensis</i>Var. <i>hibisci</i>in Makurdi, Central Nigeria

The experiment was conducted mainly to investigate the effect of change in sowing dates on disease severity of Roselle (Hibiscus sabdariffa L) leaf spot caused by Coniella musaiensis Var hibisci, plant height, number of branches, number of fruits and calyx yield of Roselle (H. sabdariffa L). Five dates were selected with an interval of fourteen days (14) between the dates for two years (2003 and 2004) to determine the most appropriate time to sow the crop using two Roselle accessions;green (Acc1) and red (Acc3).The first date was determined by the establishment of the rains in the season. It was observed that change in sowing dates had significant (p = 0.05) effect on disease severity but not on plant height, number of branches, number of fruits and calyx yield. Plants sown on July 18/27 had lowest disease indices;and are thus the best and therefore recommended for cropping of Roselle.

Effect of Organic and Chemical Fertilization on the Growth and Yield of Roselle Plants Hibiscus sabdariffa L.

This study was carried out during the growing season 2012-2013 at the fields of Agricultural Research Services in Sulaymaniyah Govemorate, to study the effect of chicken manure, sheep manure and chemical fertilizer NPK on growth, sepals, seeds yield and some chemical constituents of Roselle plants grown under Sulaymaniyah conditions. The experiment included several treatments as follows： sheep manure, 75% sheep ＋ 25% chicken, 50% sheep ＋ 50% chicken, 25% sheep ＋ 75% chicken, entire chicken manure, chemical fertilizer NPK and unfertilized control. The obtained results showed that all treatments of organic fertilization and NPK were significantly enhanced the vegetative growth parameters, sepals and concentration of anthocyanin of Roselle plants sepals. The treatment of （25% sheep ＋ 75% chicken） gave the best results： plant height （205.33 cm）, stem diameter （33.45 ram）, number of branches/plant （22.33）, total leaf area （3.29 m2）, root dry weight （56.81 g）, number of fruits/plant （110）, fresh weight of fruits （818.44 g） and dry weight of sepals （52.65 g）. But the highest concentration of anthocyanin was in the treatment of （75% sheep ＋ 25% chicken） （260.33 mg/100 g） and the lowest concentration of oxalic acid was found in the treatment of （50% sheep ＋ 50% chicken） （4.69 mg/100 g）. The results of this study showed that the use of （25% sheep ＋ 75% chicken） could enhance the vegetative growth and produce maximum yield of RoseUe calyx.

Tissue Culture and Rapid Propagation System of Roselle(Hibiscus sabdariffa L.)

[Objectives]This study was conducted to establish a tissue culture and rapid propagation system of roselle(Hibiscus sabdariffa L.)[Methods]A tissue culture and rapid propagation experiment was carried out with roselle plants as materials to study the suitable explants,the best disinfection method,the best growth medium,the best rooting medium and the transplanting and domestication method of roselle.[Results]The lateral buds of roselle were the best explants.Sterilizing with 0.1%mercuric chloride for 7 min showed a contamination rate of 5%and achieved a survival rate of 90%.With MS as the basic medium,adding 1.0 mg/L 6-BA and 0.5 mg/L IBA could obtain the best effect of bud induction.The medium with the highest proliferation rate was MS+6-BA 0.5 mg/L+BA 0.1 mg/L.On the basis of 1/2MS,adding 0.5 mg/L NAA+0.5 mg/L IBA could make adventitious buds root fastest and most,and greatly improve the propagation coefficient.And 1∶1 perlite rock:peat soil was the best transplanting substrate,with which the transplanting survival rate reached 95%.[Conclusions]This study provides technical reference for rapid cultivation and large-scale planting of roselle.

Comparative Effect of Foliar Application of Cow Dung, Wood Ash and Benlate on the Disease Initiation and Development of Roselle (Hibiscus sabdariffa L.) Leaf Spot Disease Caused by Coniella musaiensis Var. Hibisci. in Makurdi, Central Nigeria

A study on the comparative effect of cow dung, wood ash and benlate for the control of leaf spot disease of Roselle (Hibiscus sabdariffa L.) was carried out following the preparation and foliar application of the materials on selected Roselle plants of the green and red accessions (Acc1 & Acc3) in the field. The cow dung was fermented for 14 days while sour milk was added to wood ash, dissolved and all filtered and labeled. The spraying commenced soon after the plants were thinned to one and was done weekly until after 50% of the plants had flowered. Results showed significant (p = 0.05) difference between benlate, the synthetic fungicide and the bio-fertilizers (cow dung and wood ash) for the two years of the study. Disease severity was significantly lower in the benlate than in the bio-fertilizers. There was no significant difference in yield between the treatments although higher yield was recorded in benlate. Though the bio-fertilizers could not suppress infection, they aided the growth of the plants by boosting luxuriant growth. The result showed that these bio-fertilizers cannot be used as substitute to the synthetic fungicide for the control of this leaf spot disease caused by Coniella musaiensis var. hibisci. However, since they give equally good yield the bio-fertilizers can still be used to minimize the reliance upon use of chemical fungicides.

Impacts of different drying strategies on drying characteristics,the retention of bio-active ingredient and colour changes of dried Roselle

The drying kinetics of Roselle （Hibiscus sabdariffa L） of variety Terengganu （UMKL-1） and the quality attribution of Roselle were studied. The experiments were conducted using four different drying methods, including solar greenhouse drying （SD）, solar greenhouse with intermittent heat pump drying （SIHP）, hot air drying （HA） and heat pump drying （HP）. Among the four drying methods, HP achieved the highest drying rate at a range from 0.054 g H20-（g DM）-1. rain-1 to 0.212 g H20-（g DM）-1. rain 1 while SD had the lowest drying rate, measured at 0.042 g H2O. （g DM） 1.min- 1. The analysis on colour kinetics revealed that there is no significant colour loss （p 〉 0.05） observed from HP＇s dried Roselle. Greater amount of flavonoid compounds i.e. protocatechuic acid was found in SD and SIHP dried finished product whereas HP＇s dried Roselle contains higher percentage of catechin as compared to other drying methods.

Effect of Roselle calyces extract on the chemical and sensory properties of functional cupcakes

Roselle calyces(RC)are a major crop for export and used to make a common drink in Egypt.Dried RC are commercially available and appreciated to obtain concentrated extracts which might be used in the food and pharmaceutical industries for color and heath benefits.The objective of this research was to determine the chemical and the sensory properties of cupcakes formulated with Roselle calyces extract(RCE).Proximate analysis,anthocyanins,ascorbic acid,titrable acidity,%retaining of anthocyanins,color and sensory evaluations were done.RC cupcakes had high sensory scores(P<0.05)compared to control cupcakes.The parameter a*was significantly red in the RC cupcakes compared to control cupcakes along with 77%retaining of anthocyanins.The consumption of 100 g of the RC cupcakes would provide 465 mg/100 g dry matter anthocyanin that is more than 2 folds of the minimum average of the daily intake of anthocyanins for Americans,along∼1/3 of the daily dietary fiber intake to achieve fiber adequacy according to the Scientific Advisory Committee on Nutrition.RC cupcake can be a functional food and would have a“clean”label with cost effective advantage.

贮藏温度对玫瑰茄果实品质及生理特性的影响

为探究玫瑰茄在不同贮藏温度下果实品质及生理特性的变化,以桂玫瑰茄1号鲜果为试验材料,于-3(微冻)、4、8、25℃(常温)进行贮藏,通过测定失重率、腐烂率、原花青素含量、超氧化物歧化酶(superoxide dismutase,SOD)、过氧化物酶(peroxidase,POD)、过氧化氢酶(catalase,CAT)活性等指标,研究不同贮藏温度对玫瑰茄生理和品质的影响。结果表明,失重率和腐烂率随贮藏温度升高和时间延长呈上升趋势,-3℃贮藏的腐烂率和失重率最低,但出现了冷害现象。随着贮藏时间的延长,原花青素含量总体呈下降趋势,4℃贮藏的玫瑰茄原花青素含量仅在贮藏20 d时略低于-3℃,其他贮藏时间均高于其他温度;在25、8、4℃贮藏下,随着贮藏时间的延长,POD和SOD活性呈先上升后下降趋势,而-3℃贮藏下,POD和SOD活性呈下降趋势。此外,在贮藏期间POD活性随温度的升高而上升,SOD在4℃的活性均高于其他贮藏温度;CAT活性随贮藏时间的延长呈先上升后下降趋势,且在贮藏期间的活性均高于贮藏前。综上所述,低温能够较好的维持玫瑰茄的品质,延长贮藏期,4℃为其适宜贮藏温度。

超声波辅助提取玫瑰茄花青素的工艺优化

研究玫瑰茄花青素超声波辅助提取最佳工艺条件,采用pH示差法对花青素含量进行测定。在单因素试验基础上通过正交试验确定最佳提取工艺条件为固液比1∶25(g/mL),提取温度50℃,提取时间20 min,超声波功率80 W。在此最佳工艺条件下,花青素得率为0.566%。与传统浸提方法相比,得率提高了14.3%,且缩短了提取时间。

高产花色苷玫瑰茄细胞系的筛选

高产花色苷玫瑰茄细胞系的筛选杜金华郭勇（华南理工大学生物工程研究所广州５１０６４１）花色苷在植物中呈现粉红、红、紫红、紫等颜色，可以用作食品、药品及化妆品的着色剂，亦有药用价值。作为食品添加剂，颜色较合成色素自然，且安全无毒性。早在１９８７年，Ｍｉｚ...

胶园林下间作对玫瑰茄产量和品质的影响

【目的】本文研究了全周期胶园林下不同光照时长和光照强度间作区玫瑰茄的植株发育,产量表现和品质特征,为橡胶树/玫瑰茄间作模式的建立提供理论依据。【方法】根据光照时长和光照强度的差异,在全周期胶园的宽行内设置5个观测区,分析不同观测区林下间作玫瑰茄的株高,茎粗,分枝数,叶片数,单株收果数,单果重,花萼产量,花萼矿质元素和营养成分含量,评价胶园林下不同间作区玫瑰茄的产量和品质表现。【结果】①间作区不同位置玫瑰茄植株的分枝数,叶片数差异较大,均显著低于裸地对照,表现为CK>E7>M10>W7>E4>W4;②间作区M10,E7和W7玫瑰茄新鲜花萼产量显著高于E4和W4。M10单果重与裸地对照没有差异。间作区玫瑰茄平均单株收果数,单果重和新鲜花萼产量比裸地对照分别降低42.71%,26.07%和55.88%;③间作区Ca,Mg和总黄酮的含量显著低于裸地对照,而N,P,K,Fe,Zn,粗蛋白和总糖含量含量显著高于裸地对照。间作区各处理间玫瑰茄花萼营养成分差异较小。【结论】全周期胶园林下间作玫瑰茄的产量性状和显现花萼降低明显,且间作区不同位置产量差异较大,各处理间玫瑰茄花萼品质差异不大。全周期胶园林下间作区W7?E7中间6 m的位置更适宜玫瑰茄的生长,宜获得较高产量,W7?W4,E7?E4位置可种植更耐阴作物,实现橡胶林下组合种植,使经济效益最大化。

玫瑰茄培养细胞中花色苷积累的代谢调节

调整培养基组成是提高玫瑰茄（ＨｉｂｉｓｃｕｓｓａｂｄａｒｉｆｆａＬ．）培养细胞花色苷产量的有效途径之一。改变Ｂ５培养基中钙、锰、铜等离子的浓度，增加了培养细胞花色苷的积累量，其中又以锰离子最为有效，其浓度为６×１０－４ｍｏｌ／Ｌ时，花色苷产量达０．３４１ｇ／Ｌ，是对照的２．８２倍。培养基中铜离了含量为１０－４ｍｏｌ／Ｌ时，培养细胞生长受抑或死亡。高浓度的钙使培养细胞结团现象严重。外加维生素Ｃ使悬浮培养的玫瑰茄细胞产花苷能力下降。

紫苏油凝胶的制备及贮藏特性研究

紫苏油凝胶在贮藏过程中质构品质下降且易氧化,该研究通过单因素试验筛选得到紫苏油凝胶制备的最佳工艺,而后通过添加玫瑰茄提取物(复合型抗氧化剂)和Ve(单一型抗氧化剂)进行对比贮藏,利用主成分分析(PCA)综合评价抗氧化剂对紫苏油凝胶质构特性和氧化特性方面的影响。结果表明:紫苏油凝胶制备的最佳工艺为凝胶剂添加比例β-谷甾醇:大豆磷脂为7∶3(g∶g),凝胶剂添加量14%,加热温度85℃,加热时间45 min;基于主成分综合评价结果表明:若进行短期贮藏(2周以内),空白组得分最高,为3.805;若较长时期贮藏(超过3周),0.3%玫瑰茄组得分最高,为1.118。