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1.
People in vast areas of the tropics suffer from vitamin A deficiency, resulting in progressive eye damage and eventually leading
to blindness. Improving the content of vitamin A precursors in staple crops could alleviate or solve such a problem. The objective
of this work was to study the range of variability for carotene content in a sub-set of the global cassava germplasm collection,
and to determine the inheritance of carotenes, as well as their stability in response to different processing methodologies.
Genotypes with more than 2 mg carotenes/100 g of fresh roots have been selected as parental material for population development.
Although root colour is highly correlated with carotene content, a quantitative evaluation of genotypes selected by colour
is required in order to increase the efficiency of selection. Relatively few major genes are involved in the determination
of carotene accumulation in cassava roots. Stability of carotenes in response to different processing methods is genotypically
dependant, representing a trait to be evaluated after selecting for high carotene concentration in fresh roots. The results
from this work have provided the basis for defining future strategies for the improvement of the nutritional quality of cassava.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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3.
高效液相色谱-蒸发光检测法测定木薯生氰糖苷的含量 总被引：2，自引：1，他引：1
为研究所收集木薯品种叶片中生氰糖苷含量的高低,笔者将所有品种茎杆按木薯正常种植方式扦插于试验地中,在收获季节前采集顶端倒数第2叶,通过HPLC测定各品种叶片中生氰糖苷的含量。结果表明,与国外所用木薯品种‘Mcol22’相比,在笔者所测试的木薯品种中,包括热区大面积推广的‘华南5号’(SC5)和‘华南8号’(SC8)中,大部分生氰糖苷含量都不高,其中‘Q10’生氰糖苷最低,每克鲜重只有11.3μmol,大约是最高含量‘Ecu81’的1/4。研究结果为筛选低生氰糖苷含量的木薯资源提供了一个参考。 相似文献
4.
Introgression of antioxidant activity into cassava (Manihot esculenta C.): an effective technique for extending fresh storage roots shelf life 
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下载免费PDF全文 Physiological postharvest deterioration (PPD) of cassava is the main constraint affecting its nutritional and economical values. PPD is induced by wounds when detaching storage roots from mother plant during harvesting. It is accelerated by the reactive oxygen species (ROS) such as oxygen ion (O2) and peroxide (O2)?2. The carotenoid content and its antioxidant property can help in extending shelf life of cassava storage roots. The primary mode of action of carotenoids as antioxidant is to quench singlet oxygen. Cassava breeding was reported to successfully introgress and improve carotenoid content into cassava. The two types of phytoene synthase (PSY) enzymes (PSY1 and PSY2) are key regulators of carotenoids accumulation in cassava. Carotenoids formation and accumulation in cassava storage roots are induced by a single nucleotide polymorphism in PSY2 which causes a non‐conservative amino acid exchange. This single nucleotide polymorphism in PSY gene is co‐segregated with β‐carotene in cassava storage roots, a phenomenon that could help to unravel the mechanism of introgression of carotenoids into cassava. This article investigates breeding feasibility for improving quality of cassava landraces in developing countries. 相似文献
5.
Jonathan Mkumbira Linley Chiwona-Karltun Ulf Lagercrantz Nzola Meso Mahungu John Saka Albert Mhone Mpoko Bokanga Leon Brimer Urban Gullberg Hans Rosling 《Euphytica》2003,132(1):7-22
Cassava roots, a major food in Africa, contain cyanogenic glucosides that may cause toxic effects. Malawian women farmers
considered fields of seemingly similar cassava plants to be mixes of both ‘cool’ and ‘bitter’ cultivars. They regard roots
from ‘cool’ cultivars as non-toxic. Roots of ‘bitter’ were considered to require extensive traditional processing done by
women to be safe for consumption. But curiously, these women farmers preferred ‘bitter’ cultivars since toxicity confers protection
against theft, which was a serious threat to the food security of their families. We studied how well these farmers comprehend
the effects of genetic variations in cassava when dealing with cyanogenesis in this complex system. Using molecular markers
we show that most plants farmers identified as belonging to a particular named cultivar had a genotype typical of that cultivar.
Farmers' ethno-classification into ‘cool’ and ‘bitter’ cultivars corresponded to a genetic sub-division of the typical genotypes
of the most common cultivars, with four-fold higher cyanogenic glucoside levels in the bitter cultivars. Examining morphology,
farmers distinguished genotypes better than did the investigators when using a standard botanical key. Undoubtedly, these
women farmers grasp sufficiently the genetic diversity of cassava with regard to cyanogenesis to simultaneously benefit from
it and avoid its dangers. Consequently, acyanogenic cassava – the breeding of which is an announced good of some cassava genetic
improvement programmes – is not a priority to these farmers. Advances in molecular genetics can help improve food supply in
Africa by rapid micropropagation, marker assisted breeding and introduction of transgenic varieties, but can also help to
elucidate tropical small-scale farmers' needs and skills.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
6.
采用高效液相色谱检测60个不同玉米籽粒颜色自交系中类胡萝卜素（叶黄素、玉米黄质、β-隐黄质和β-胡萝卜素）含量,结果显示,叶黄素、玉米黄质、β-隐黄质和β-胡萝卜素的平均含量分别为56.32、0.85、1.31和5.75mg/kg。按籽粒颜色由浅到深,将60个玉米自交系分为4个等级,颜色越深的品种类胡萝卜素含量越高。对R、G、B、Gray值与类胡萝卜素含量进行相关分析表明,R、G、B和Gray值之间存在极显著正相关（P<0.01）,相关系数分别为0.992（G与Gray）和0.939（R与Gray）,4种类胡萝卜素含量间呈极显著正相关,相关系数分别为0.830（β-隐黄质与β-胡萝卜素）和0.815（β-隐黄质与玉米黄质）。根据类胡萝卜素含量对60个玉米自交系进行聚类分析,60个自交系分为5类,其中第1类类胡萝卜素含量最低,第2类属于中富含类胡萝卜素的自交系,第5类属于高维生素A含量的自交系。综上可知,类胡萝卜素的种类及其含量是影响籽粒颜色的重要因素,可为培育高胡萝卜素含量的玉米品种提供依据。 相似文献
7.
2005年采用高胡萝卜素、低干双亲的特殊组合‘浙薯81’ב浙薯255’创制出甘薯优异高干红肉品种‘浙薯13’。为了探索甘薯胡萝卜素含量、干率聚合育种新方法,2016年对这一双亲的正反交组合F1胡萝素含量、干率进行了测定和遗传分离规律分析。结果表明,正反交组合的胡萝卜素含量遗传主要受非加性效应控制,组合传递力分别为45.32%和49.73%。干率不仅存在加性效应,而且呈明显的超亲遗传,正反交组合的超亲优势分别达到15.12%和12.75%,超高亲率约70%,呈现相当于高干×低干的遗传分离,中、高干类型比例高达60%左右,其中高干类型比例约28%。杂交后代含有干率≥25%、胡萝卜素含量≥3 mg/100 g FW的株系占26.10%,含有干率≥25%、胡萝卜素含量≥10 mg/100 g FW的株系占9.78%。干率是甘薯食味的主要影响因子。因此,‘浙薯81’与‘浙薯255’杂交可以高效地聚合胡萝卜素含量和干率,大幅度提高优质食用高胡萝卜素育种的筛选效率。 相似文献
8.
亚麻苦苷和百脉根甙等氰化物是木薯块茎、茎叶等组织或器官中的剧毒物质,细胞色素p450是调控氰化物生物合成的关键酶基因,克隆有关酶基因对于理解木薯氰化物代谢和通过转基因对木薯氰化物的改良具有重要意义。根据国际数据库中的木薯氰化物合成限速酶基因序列信息,设计特异引物,通过同源克隆法,从木薯中克隆出1626bp cDNA基因序列。序列分析表明,克隆基因共编码541个氨基酸,与数据库中的木薯CYP79D2基因在核苷酸序列、氨基酸序列同源性上均达到99％,并含有相应基因家族的保守区域,确定克隆到木薯CYP79D2全长基因。 相似文献
9.
Cassava roots have a short shelf life due to a process known as post-harvest physiological deterioration (PPD). Within 2–3 d undesirable vascular streaking in the root develops. Tolerance to PPD was recently reported in different cassava genotypes, opening up new opportunities to analyze biochemical changes in stored roots and in the functional properties of their starches. Roots from PPD-susceptible (HMC-1) and tolerant (AM 206-5) clones were harvested and stored for up to 14 d in ambient tropical conditions. AM 206-5 is also characterized by amylose-free starch. Roots and starch were analyzed each day. PPD levels differed significantly between the two clones (35% and 8% at day 14) and showed a relation to scopoletin synthesis, which reached maximum levels around day 3 or 4 of storage. Roots lost weight consistently during storage (≈10% in two weeks). Starch loss per day of root storage was estimated at about 1%. This could be the result of consistent increases in total sugars and respiration of root tissue. Important changes in starch properties were observed. Gel clarity decreased gradually during storage, with more pronounced changes occurring in starches from HMC-1. Swelling power decreased only in the case of AM 206-5. Gel viscosity increased in both genotypes. Improved tolerance to PPD could significantly reduce the economic impact of the short shelf life of ordinary cassava root processing. It remains to be seen, however, whether changes in stored roots positively or negatively affect the quality of the final product. 相似文献
10.
A protocol was established for high frequency cyclic somatic embryogenesis for different varieties of cassava. An efficient
plant regeneration system was developed for the high cyanogenic variety PRC60a. Linamarin content and linamarase activity
were determined in various tissues of secondary somatic embryos and regenerated plants of PRC 60a. Both linamarin and linamarase
activity were not detected in embryogenic callus, roots induced from callus and somatic embryo tissues. The stems and leaves
of regenerated plants (in vitro) and storage roots and leaves of mature plants (in vivo), however, contained variable amounts of linamarin and linamarase activity whereas in the non storage root tissues (in vitro) only linamarin was detected. The present study suggested that the linamarin biosynthetic pathway may be absent or not switched
on in the embryogenic callus and somatic embryos. The ploidy level and somatic chromosome number of the regenerated plants
were found to be same as the source plants. The availability of this regeneration system would be useful not only for investigating
cyanogenesis but also for genetic manipulation in cassava.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
11.
苦瓜种质资源的形态学性状和营养成分的多样性分析 总被引：6，自引：3，他引：3
苦瓜种质资源的形态学性状和营养成分具有多样性,为比较各种特征性状变异程度的大小,本试验在对44个苦瓜品种（系）的26个形态学性状调查以及反映果实营养成分的5项指标进行测定的基础上,对其进行统计分析。结果表明：（1）在形态学性状方面,果形、果色、单果重、瓜瘤的大小,单瓜的种子数在品种（系）之间差别大,而植株的分枝性、瓜横茎以及种子的花纹等性状则差别小;（2）在营养成分方面,含水量在品种（系）间差别最小,而蛋白质含量差别最大,其次是维生素C的含量。 相似文献
12.
Marwa Aouida Fred Rook Alexandra Bianca Maimann Raquel Snchez‐Prez Ghassen Abid Marie Laure Fauconnier Moez Jebara 《Plant Breeding》2019,138(3):348-359
Common vetch (Vicia sativa L.) is an important annual forage legume. It is used as a cover crop, green manure, pasture legume and for silage and hay production. Its seeds can be used as a source of highly digestible protein and minerals in animal diets. However, their utilization as a feedstuff for monogastric animals is hindered by the fact that the seeds contain cyanogenic antinutritional factors that reduce their palatability. An effective utilization of V. sativa seeds as a successful monogastric feed stuff requires selection for higher protein availability and minimization of the cyanogenic antinutritional factors content. In this study, we selected one natural accession named Mjez Ibeb, from a collection of 25 accessions and cultivars, based on its superior agronomic performance and its naturally occurring genetic variation for cyanogenic traits. We investigated the genetic variation that exists for the cyanogenesis trait in more detail and analysed the seeds of 133 lines derived from accession Mjez lbeb. Of these, 40 naturally polymorphic lines that showed deficiencies in cyanogenesis and cyano‐amino acid content, were subsequently selected for detailed chemical analysis. Cyanogenic glucosides and cyano‐amino acid concentrations varied widely in the 40 lines. Multivariate analysis was performed and three lines (L16, L21, L18) with low content of cyanogenic compounds were identified. 相似文献
13.
P. Kakes 《Euphytica》1990,48(1):25-43
Summary Cyanogenesis, the production of HCN is a trait that can be found in all the major taxa. The system is particularly important in higher plants, both in view of the specialized mechanisms found in plants and with regard to the physiological and ecological function of HCN production. The present paper discusses the long history of cyanogenic research, the distribution of the cyanogenic substances among the taxa of higher plants, their localisation in the plant organs and their biosynthetic pathways. The same topics are discussed with regard to the specialized -glucosidases found in plants that play a role in the catabolism of the cyanogenic substances and in HCN production.The physiological and ecological functions of the cyanogenic systems are discussed with emphasis on the few species studied so far that are polymorphic, i.e. contain cyanogenic and acyanogenic individuals in the same population. Although research in this area is still in its infanthood, it is clear that cyanogenesis is part of a complex system that among others, gives protection against particular groups of herbivores. Apparently the defensive system is under some kind of constraint, developmental, selectional, or both, that prevents plants from having an absolute defense against herbivores. One such constraint viz. a negative effect of the cyanogenic system on growth and/or reproduction is discussed in some length. A number of cultivated species, i.e. cassava (Manihot esculenta), sorghum (Sorghum spp) and lima bean (Phaseolus lunatus) to mention a few, are cyanogenic. Cyanogenesis in species used for human or lifestock consumption is generally considered an undesirable trait. On the other hand low levels of cyanogenesis may cause greater susceptibility to herbivores and consequently lower the yield. Apparently cyanogenesis is a character of interest for plant breeders trying to improve cyanogenic species. 相似文献
14.
13份木薯种质资源多样性分析与系统评价 总被引：2，自引：1，他引：1
为选育优良的木薯新品种,对13份优良木薯种质资源的农艺性状进行鉴定,分析其遗传多样性特点。结果表明,13份资源在叶片形状、叶片颜色、叶裂数、叶柄颜色、叶脉颜色、主茎内外皮颜色、幼茎颜色、茎杆生长情况、株型、茎分叉、分枝角度、株高、主茎高度、主茎直径、块根分布、结薯集中度、块根形状、块根内外皮颜色、块根肉质颜色等方面均表现出多样性,且收获指数、淀粉含量、干物质含量等存在较大差异。本研究对13份木薯种质资源进行了系统评价,筛选获得了5个优良新品系,为今后木薯种质资源分类提供了参考。 相似文献
15.
旨在降低或去除木薯的生氰糖苷,获得安全无毒木薯新品种。本研究以高氰和低氰5 个品种的木薯为材料,通过RT-PCR 方法,研究了生氰葡萄糖苷酶基因Linamarase 在木薯中的表达情况。木薯Linamarase 基因只在地上部分表达;5 个木薯品种,包括低氰和高氰品种,在块根中也均未检测到Linamarase 基因的表达。在地上部分中,顶芽的表达量要远远大于茎和成熟叶片的表达量,而且低氰和高氰品种在顶芽的表达量基本相同,但是低氰品种茎及成熟叶片中Linamarase 的表达量比高氰品种相对较高。木薯生氰糖苷酶Linamarase 在不同木薯品种不同组织的表达情况的不同,可以为筛选安全无毒木薯品种提供一个参考。 相似文献
16.
14-3-3蛋白结构与功能预测及其在木薯成熟期的表达分析 总被引：1，自引：0，他引：1
为了深入研究木薯14-3-3蛋白结构和功能,也为研究木薯块根淀粉积累的分子调控提供新思路。本研究采用生物信息学方法对木薯14-3-3蛋白家族的组成成分与理化性质、系统发育进化、导肽、亚细胞定位、二级结构、功能结构域、三级结构及亲水性、疏水性进行分析和预测,并对14-3-3基因在不同木薯品种中进行差异表达分析。结果表明：（1）木薯14-3-3蛋白家族16个异构体存在多个不同的保守结构域,二级结构相似的亲水性蛋白家族成员在进化关系上可划分为2大不同的类别;（2）14-3-3基因家族16个成员在花叶木薯、ZM-Seaside和华南9号(SC9)块根成熟期的表达水平存在显著性差异(P<0.05),与花叶木薯和SC9相比,产量较高的木薯品系ZM-Seaside块根中14-3-3基因表达水平显著下降(P<0.05),推测14-3-3蛋白在木薯块根成熟期的淀粉积累过程中可能起着负调控作用。 相似文献
17.
Summary The two most serious diseases of cassava (Manihot esculenta
Crantz) are cassava mosaic disease (CMD) and cassava bacterial blight (CBB) (Xanthomonas manihotis
Starr). Clone 58308, derived from the third backcross of the interspecific cross of cassava (M. esculenta) x ceara rubber (M. glaziovii), showed a high level of resistance to both diseases. Crosses of 58308 with several other clones which varied from susceptible to moderately susceptible to both diseases gave progenies with a significant genotypic correlation between resistance to both diseases (r=0.90), apparently due to linkage. The heritabilities of resistance to the diseases were estimated at 50–70% for CMD and 25–65% for CBB. Resistance to both diseases is assumed to be polygenic. The correlated response to selection for CMD and for CBB was estimated. 相似文献
18.
The presence and morphology of plant brace roots are important root architecture traits. Brace roots contribute significantly to effective anchorage and water and nutrient uptake during late growth and development, and more importantly, have a substantial influence on grain yield under soil flooding or water limited conditions. However, little is known about the genetic mechanisms that underlie brace root traits. In this study, quantitative trait loci (QTLs) for presence of brace roots from the sorghum landrace “Sansui” were mapped and associated molecular markers were identified. A linkage map was constructed with 109 assigned simple sequence repeat markers using a F2 mapping population derived from the cross Sansui/Jiliang 2. Two QTLs associated with presence of brace roots were localized on chromosomes 6 and 7. The major QTL on chromosome 7 between markers Dsenhsbm7 and Xcup 70 explained about 52.5% of the phenotypic variation, and the minor QTL on chromosome 6 was flanked by Xtxp127 and Xtxp6 and accounted for 7.0% of phenotypic variation. These results will provide information for the improvement of sorghum root architecture associated with brace roots. 相似文献
19.
Miyuki Kunihisa Shigeki Moriya Kazuyuki Abe Kazuma Okada Takashi Haji Takeshi Hayashi Hoytaek Kim Chikako Nishitani Shingo Terakami Toshiya Yamamoto 《Breeding Science》2014,64(3):240-251
Many important apple (Malus × domestica Borkh.) fruit quality traits are regulated by multiple genes, and more information about quantitative trait loci (QTLs) for these traits is required for marker-assisted selection. In this study, we constructed genetic linkage maps of the Japanese apple cultivars ‘Orin’ and ‘Akane’ using F1 seedlings derived from a cross between these cultivars. The ‘Orin’ map consisted of 251 loci covering 17 linkage groups (LGs; total length 1095.3 cM), and the ‘Akane’ map consisted of 291 loci covering 18 LGs (total length 1098.2 cM). We performed QTL analysis for 16 important traits, and found that four QTLs related to harvest time explained about 70% of genetic variation, and these will be useful for marker-assisted selection. The QTL for early harvest time in LG15 was located very close to the QTL for preharvest fruit drop. The QTL for skin color depth was located around the position of MYB1 in LG9, which suggested that alleles harbored by ‘Akane’ are regulating red color depth with different degrees of effect. We also analyzed soluble solids and sugar component contents, and found that a QTL for soluble solids content in LG16 could be explained by the amount of sorbitol and fructose. 相似文献
20.
Eder Jorge de Oliveira Carolina Vianna Morgante Saulo de Tarso Aidar Agnaldo Rodrigues de Melo Chaves Rafaela Priscila Antonio Jailson Lopez Cruz Maurício Antônio Coelho Filho 《Euphytica》2017,213(8):188
The development of cassava (Manihot esculenta Crantz) with a high yield under water-deficit conditions is one of the goal of the breeding programs. The objective of this study was to evaluate the performance and to select cassava accessions based on drought tolerance indices and productive potential under water stress. Forty-nine accessions were evaluated for five agronomic traits (plant height—PH, root yield—RoY, shoot yield—ShY, harvest index—HI; and dry matter content of roots—DMC) under full irrigation conditions and drought stress (DS). The accessions were selected based on: (i) high yield under drought conditions (HY-DS) and (ii) high drought tolerance (Dr-To) based on six different indices. Overall, water stress dramatically reduced the traits’ means (RoY—72.98%, ShY—54.95%, DMC—26.15%, HI—31.05%, and PH—32.95%). Low coincidence among the top ten accessions was identified based on HY-DS and Dr-To criteria. Therefore, considering only the most important traits (RoY and ShY), five accessions (BGM0815, BGM0598, 9624-09, BGM0818, and BRS Formosa) presented high HY-DS. In contrast, to Dr-To criterion, eight and nine accessions were selected for high yield of the aerial part (ShY and PH) and roots (RoY and DMC), respectively. The mean productivity, geometric mean productivity, and drought tolerance indices were the most promising to identify genotypes with high agronomic attributes, while drought susceptibility index, susceptibility, and yield stability index were suitable to identify the most drought tolerant accessions. This set of selected accessions can be used in breeding programs aimed at high yield and drought tolerance. 相似文献