Variation of sweet potatoes with respect to source potentials and sink capacities

Summary By using four tester clones either as scions or stocks, source potentials and sink capacities of two groups of 13 and 20 sweet potato clones were measured in 1986 and 1987, respectively. Results obtained in the 1986 trial were generally consistent with those in the 1987 trial, though different clones were used in both trials. There were significant differences in source potentials and in sink capacities among tested clones. Responses of source to sink and of sink to source were also estimated using a regression method. No significant correlation was observed between source potential and response of source to sink. However, sink capacity showed significant relationship with response of sink to source.     

甘薯库源关系及其遗传研究初报

该文选用几种不同类型的甘薯（Ｉｐｏｍｏｅａ ｂａｔａｔａｓ Ｌａｍ），品种相互嫁接。嫁接组合块根的鲜产，干产分别进行方差分析。结果表明，光合源和贮藏库的遗传生理特性对嫁接组合块垠的产量重要作用，库容量大小时甘薯地下部块根产量起重要的决定作用，同时，高库容丰木克服或改善低关类型品种的潜在光合源和潜在生理流，并提高后者的光效能和块根产量，甘薯地下部块根的干物率和薯肉色也是贮藏根固有的遗传生理特性，嫁接     

Ethylene production as a possible indicator of wound healing in roots of several sweet potato cultivars

Summary Fleshy roots of 18 sweet potato cultivars were wounded and cured for 12 days. Significant differences were found between cultivars for ethylene production, cell lignification, and wound periderm formation. Average ethylene production, the number of days ethylene was produced, or the day of peak ethylene production showed nonsignificant and low (r²=0.40) correlations with cell lignification or wound periderm formation; however, multiple regression analysis indicated statistically significant and moderate correlations between selected daily ethylene production and cell lignification (r²=0.74) and wound periderm formation (r²=0.73). These observations suggest that measurement of ethylene produced by wounded sweet potato roots may be useful in helping screen large numbers of sweet potato breeding lines and their progeny for the ability to produce lignified and wound periderm cell layers. Wound healing, however, is only one aspect of good storage capability in sweet potato cultivars.     

Adaptation and stability analysis of sweet potato varieties for low-input systems in Uganda

Sixteen sweet potato varieties were evaluated for fresh storage root yield in 20 trials during 2000–2001 for three seasons in four locations in Uganda. Of the 16 varieties, 11 were developed by farmers and five by a central breeding programme. The behaviour of the varieties was quantified in terms of wide adaptation (genotypic mean across trials), specific adaptation (genotypic predictions for specific locations) and stability (Shukla stability variance). With respect to all three aspects of yield behaviour, farmer varieties performed on average better than the official varieties. The results illustrate the potential that farmer varieties can have in the improvement of sweet potato in Uganda and other regions where high diversity of sweet potato landraces exists.     

3种专用型甘薯光合光响应曲线及其模型拟合

为了揭示甘薯光合光响应特性,并为其筛选出最佳的光合响应曲线拟合模型,准确求得光合主要参数,运用直角双曲线模型、非直角双曲线模型、指数函数模型以及直角双曲线修正模型的方法分别对3种专用型甘薯（鲜食型甘薯、淀粉型甘薯和花青素型甘薯）叶片的光合光响应曲线进行拟合。直角双曲线模型拟合的最大净光合速率(Pnmax)和暗呼吸速率(Rd)远大与实测值,光饱和点(Isat)小于实测值,非直角双曲线模型拟合的Pnmax大于实测值,Isat则远小于实测值,而指数函数模型拟合的Isat、Rd和光补偿点(Ic)均远小于实测值;只有经直角双曲线修正模型拟合所得的光合参数值最接近实测值,且能拟合甘薯光合光响应曲线的光抑制部分。通过比较3种类型甘薯光合特性可知,鲜食型甘薯和淀粉型甘薯的Pnmax和Isat均高于花青素型甘薯,但各类型甘薯的Ic和Rd无明显差异。直角双曲线修正模型所求得光合参数值最接近实测值,日后可运用该模型准确、高效地研究甘薯光合特性;鲜食型甘薯和淀粉型甘薯具有更大的光强适应范围和光合产物的积累潜力。     

甘薯细胞壁蔗糖转化酶基因IbCWIN家族成员鉴定及表达分析

甘薯是重要的粮食、饲料、工业原料作物和新型的生物能源作物,细胞壁蔗糖转化酶是植物源、库组织蔗糖代谢的关键酶,但关于甘薯细胞壁蔗糖转化酶基因IbCWIN家族成员的研究尚未见报道。本研究测定供试品种不同组织部位的蔗糖淀粉含量,利用生物信息学方法对IbCWIN基因家族的理化性质、保守结构域、系统进化关系、启动子作用元件、组织特异性表达模式进行分析。结果表明,甘薯茎中蔗糖含量最高,须根和叶次之,块根最低;块根淀粉含量最高,极显著高于其他部位。甘薯中含有10个IbCWIN基因,编码氨基酸442～1115个,蛋白质分子量范围49.56～124.44kD,等电点为5.0～9.1。分布在8条染色体上,都含有Glyco₃2保守结构域及相同或相似的保守基序motif,属于糖基水解酶基因家族GH32。IbCWIN与木薯MeCWINV同源性高, IbCWIN基因家族启动子区域含有多种类型的顺式作用元件。qRT-PCR结果表明,IbCWIN基因家族在甘薯不同组织中均有表达且有多种表达模式,其中IbCWIN2和IbCWIN9在块根中表达量显著高于其他组织部位。本研究为下一步探索甘薯IbCWI...     

Regression analysis of genotype x environment interaction in sweet potato

Summary Two experiments, each involving a set of 10 sweet potato clones, were conducted for three years at 4 sites (Ekona, Ebolowa, Nkolbisson, and Bambui Plain) in Cameroon. Data obtained were subjected to analysis of variance to determine the presence of genotype x environment (G x E) interactions, and to regression analysis to assess the performance of clones across anvironments. Environments were assessed in two ways: (i) the mean response of all clones (dependent assessment), and (ii) the average performance of a different set of clones (independent assessment).The first experiment (Expt 1) produced higher yields but had fewer stable clones than the second (Expt 2).The analysis of variance revealed that the clones interacted significantly with environments for all traits.The study has identified high yielding and stable sweet potato clones for distribution to growers in the major areas of cultivation in the tountry. Despite slight differences in numbers of clones judged stable by the various regression indices in the two methods of environmental assessments, the rankings of clones on the basis of their linear regression coefficients were similar. In a developing country like Cameroon, with limited resources and where sophisticated equipment for obtaining physical or biological measures of the environment may be lacking, the mean performance of genotypes may still be the most reliable measure of environment in evaluating the stability of performance of crop cultivars.     

云南黄心甘薯地方品种特性分析

１９９６～１９９７年对征集到的２４份云南黄心甘薯地方品种资源进行了农艺性状、生长特性、抗逆性、生产力及营养品质的分析、评价，结果表明：蒙自黄心、红鸡窝、普洱黄山芋、紫红皮、甘心红薯、路南红皮、东川白花等一批黄心地方品种生长势强、适应性强、块根产量高、品质优，开发利用潜力较大。     

甘薯小象甲对不同甘薯品种的趋性反应试验

成虫取食主要取决于气味诱导和对物体性状的偏好,为了解小象甲对不同品种甘薯气味的选择性与品种抗虫的相关性;选取14个甘薯品种,利用Y型嗅觉仪测定小象甲对14个甘薯品种进行气味选择试验,并计算各品种的抗性。结果显示,小象甲对14个不同品种甘薯的反应率、诱集率以及选择系数都具有差异显著性,小象甲对14个甘薯品种的反应率在0.3~1之间,不同品种对甘薯小象甲的诱集率在0.2~0.9556之间,小象甲对不同甘薯品种之间的选择系数在-0.03~0.91之间,其中‘鄂薯15’选择系数最小为-0.03,表现为最抗小象甲;‘鄂薯6号’和‘商薯19’的选择系数最大且都为0.91,表现为最感小象甲。本研究为甘薯小象甲的防治奠定了基础,对今后完善抗甘薯小象甲品种的鉴定工作有很大帮助。     

种植密度、氮肥和水分胁迫对玉米产量形成的影响

为阐明种植密度、氮肥和水分胁迫对不同玉米品种产量形成的影响,选用6个玉米品种,在两种密度(45 000株 hm^-2和75 000株 hm^-2)、两种施氮水平(纯氮112.5 kg hm^-2和337.5 kg hm^-2)和两种水分(前期干旱控水和正常灌水)处理下进行大田试验,调查玉米源库性状的主要生理参数和籽粒产量。结果表明,在环境压力较小时(低密度、高氮和正常灌水),玉米品种间籽粒产量、源性状(叶面积指数、穗位叶净光合速率和群体源供应能力)、库性状(群体库容量)、源库协调性状(群体库源比值、籽粒灌浆速率和收获指数)以及成熟期干物质积累量和吐丝期至成熟期干物质积累量差异较小,而逆境胁迫下(高密度、低氮和干旱),差异较大。环境压力较大时(高密度、低氮和干旱),叶面积指数、群体源供应能力、成熟期干物质积累量、吐丝期至成熟期干物质积累量、群体库容量和收获指数与籽粒产量呈显著或极显著正相关。由此说明,在玉米品种产量改良中要强化逆境人工选择,以适应自然选择,改善玉米品种逆境下的群体源库性状,增强吐丝期至成熟期叶片的光合生产效率,强源促库,提高逆境下的生产能力和适应性。     

七个紫甘薯品种块根花色苷含量的比较

运用紫外-可见分光光谱法,对引自日本和徐州并在云南昆明种植的7个紫甘薯品种进行分析,研究了不同甘薯品种块根中花色苷含量及其在同一块根中的分布和花色苷产量。结果表明:不同品种花色苷含量和产量差异显著,花色苷含量以徐13-4含量最高,为107.22mg/100gFW;花色苷产量以种子岛紫最高,达13036.5g/hm²,其次是徐13-4,为11663.7g/hm²;花色苷在块根中的分布不均匀,含量表现为块根表皮>中心组织>薯肉。徐13-4可作为选育花色苷专用品种的亲本,种子岛紫可作为企业生产花色苷原料的品种加以利用。     

水培甘薯的光合研究

使用LI-6400便携式光合测定系统对三种水培甘薯食用型南薯88、兼用型徐薯18和特用型南紫薯008的光合进行了测定,利用非直角双曲线模型对三种甘薯品种的光合作用生理参数进行拟合。结果表明,不同类型甘薯品种的光响应曲线的特征参数存在着差异,食用品种南薯88的光和潜力最强,可在高密度栽培下发挥群体优势达到高产;兼用型品种徐薯18对光的适应性次之,在较高密度栽培下能发挥群体优势;特用型品种南紫薯008的光合潜力和对光的适应性均最弱,但对弱光的利用率最高,最适合于间套作。不同类型甘薯品种间的生理指标存在相似的变化,气孔导度和蒸腾速率对净光合速率的影响达极显著正相关,胞间CO2浓度对甘薯净光合速率的影响呈极显著负相关,揭示了不同类型甘薯品种在光能利用上的差异。南紫薯008在较低光强下能很快使气孔打开,蒸腾速率也快速增加,从而使光合速率也加强。在高光强下,南薯88的气孔导度、胞间CO2浓度值最大,这可能是南薯88光合速率高的原因。为田间甘薯的共性和特异性研究提供了一定的理论基础。     

安徽省甘薯生产现状及发展分析

[目的][方法]通过对安徽省近几年甘薯生产和消费情况进行调研,分析安徽省甘薯产业现状及存在问题,探求甘薯产业发展潜力和对策,以期为产业发展相关政策的制定提供依据。[结果]调研结果：安徽省甘薯种植分春薯和夏薯2种种植方式,当前种植品种共有40个,其中主栽品种17个。在主栽品种中,淀粉专用型品种占53.0%,鲜食型占35.0%,兼用型占12.0%。所种植品种以外引为主,占73.5%,本省自育品种较少,仅占26.5%。全省甘薯的消费比例以加工为主,鲜食为辅。研究指出了安徽省甘薯生产存在政府重视程度不够,机械化水平落后,品种更新换代慢、专用品种缺乏、种苗繁育体系不健全,病害严重,生产技术水平低下,加工企业规模小、产品附加值低的主要问题。[结论]提出培育专用新品种,加大科技示范推广力度,大力发展机械化生产,加工企业联合研发甘薯深加工产品,提高甘薯附加值等对策。     

不同类型甘薯茎和叶中碳、氮、磷化学计量学特征研究

选取3个鲜食型、3个淀粉型和3个紫甘薯品种,于不同生育期采集地上部茎、叶样品,测定其碳（C）、氮（N）、磷（P）含量,研究不同类型甘薯C、N、P生态化学计量学特征及其随生育期的变化规律。结果表明,甘薯叶中C、N、P含量范围分别为391~399、26.3~29.1、2.90~3.10mg/g,茎中分别为421~428、11.6~15.2、4.99~5.77mg/g,其在茎、叶中的差异大于甘薯类型间的差异;茎中C含量随生育期延长略有增加,但茎、叶中N和P含量则随生育期延长而降低,茎、叶中C、N、P含量随生育时期的变化大于甘薯类型间的变化。不同类型甘薯叶中C/N、C/P分别以紫甘薯和淀粉型甘薯最大,说明紫甘薯和淀粉型甘薯有较高的碳同化能力;3种类型甘薯叶中N/P为8.57~9.97,表明N元素是甘薯茎叶生长的主要限制因子。     

Difference in Allelopathic Potential as Influenced by Root Periderm Colour of Sweet Potato (Ipomoea batatas)

Laboratory bioassay and high‐performance liquid chromatography (HPLC) analysis were conducted to determine the allelopathic potentials of aqueous or methanol extracts from three different coloured sweet potato [Ipomoea batatas L. (Lam)] cultivars by plant part. The aqueous extracts applied on filter paper significantly inhibited root growth of alfalfa (Medicago sativa L.). Aqueous leaf leachates at 40 g dry tissue l^?1 (g l^?1) from white sweet potato cultivar ‘Sinyulmi’ showed the highest inhibition against alfalfa, followed by yellow ‘Sinhwangmi’ and purple ‘Jami’. Alfalfa root growth was significantly inhibited by methanol extracts of the same plants as the concentration increased. Aqueous and methanol extracts from leaves showed the most inhibitory effect on alfalfa root growth followed by stems and roots. By means of HPLC analysis, leaf samples of sweet potato had the highest amount of phenolic compounds followed by stems and roots. Total content of these compounds was highest for leaf extracts (37.7 mg 100 g^?1), detected in EtOAc fraction, especially trans‐cinnamic acid (20.9 mg 100 g^?1). These results suggest that sweet potato plants are allelopathic and that their activities differ depending on plant part as well as root periderm colour.     

甘薯实生系与其无性系性状相关关系及早期选择利用研究

甘暮实生系是分离世代,其性状的变异与资源品种表现同一趋势,与其无性系在诸多性状上呈强弱不同的正相关关系,这是对实生系进行早期选择利用的基础.根据结薯性可将实生系分为成薯、膨大和直根3个类型,成薯系%因组合而异,受环境影响不明显.5年的研究结果证明:无性系类型间的产量性状有明显差异,从成薯类型选育高产新品系的入选率高.在此问题上和美国Granberry.M.等的认识不同.建议把我国甘薯育种的初选期提早到实生系时期,以缩短育种周期,提高育种效率.笔者认为把甘薯杂交种子培育的株系,定名为实生系,比较确切.     

Somaclonal variation in explant-derived potato clones over three tuber generations

Summary Tuber characteristics of potato clones (Solanum tuberosum L.) regenerated from cultured leaf, rachis or stem pieces of cv. Desiree were assessed in field trails over three years. In the first two seasons, when the crop was grown for seed potato production, tuber numbers and the tuber yields were normally distributed and the population means of the clones were about the same as those of the controls. When 78 of the clones were grown as a ware crop in a replicated field trial there were statistically significant differences between most clones and the controls in total yield (generally lower) and ware yield (generally higher), brought about by alterations of the size distributions of tubers. In all years the population of clones had fewer scab (Streptomyces scabies) lesions than the controls. Clones with consistent differences in flesh colour and eye depth were also observed. Two out of 78 clones, in 1984, had significantly higher dry matter content. No stable decrease in susceptibility to the cyst nematode Globodera pallida was observed amongst 167 clones tested. These potato plants regenerated from explants clearly show that somaclonal variation can include agronomically relevant changes.     

不同因素对甘薯根系发育的影响

选用3个不同基因型的甘薯品种,采用正交试验设计,研究了百苗重和施肥量对甘薯块根的形成,特别是甘薯块根结薯个数的影响。结果表明,品种、百苗重及施肥量对甘薯根系发育有显著影响,南薯88在百苗重为4.0kg和不施肥条件下其根系重量和块根数量显著优于其他水平,同时南薯88根系数量最高。     

The Differences in Grain Weight and Quality Within a Rice (Oryza sativa L.) Panicle as Affected by Panicle Type and Source-sink Relation

The effects of panicle type and source‐sink relation on the variation in grain weight (GW) and quality within a panicle were investigated using four japonica (Oryza sativa L.) varieties differing in grain density and two source‐sink adjusting treatments. There were significant differences in GW and filling grain percentage (FGP) among superior and inferior grains for compact‐panicle varieties (Xiushui 994 and Xiushui 63), while not for loose‐panicle ones (Xiushui 11 and Chunjiang 15). The floret‐removal treatment significantly improved the development of inferior florets and reduced the differences in FGP and GW between superior and inferior grains for the compact‐panicle variety, while leaf‐deleting treatment reduced FGP and GW of both superior and inferior grains. For the loose‐panicle varieties, the two treatments had little effect. The difference in chalky grain percentage (CGP) and amylose content (AC) between the two kinds of florets was larger in compact‐panicle varieties than in loose‐panicle ones. Both floret‐removal and leaf‐deleting treatments caused the changes in CGP and AC of superior or inferior grains for compact‐panicle varieties, but not for loose‐panicle ones. The difference in starch content (SC) between superior and inferior grains was much larger for Xiushui 994 than for Xiushui 11, and the two varieties differed in the response of SC to the change of source‐sink relation. The differences in AGP‐glucose pyrophosphorylase (ADPG‐Ppase), starch branching enzyme (SBE) and soluble starch synthase (SSS) activities between the two kinds of grains were basically same for the two varieties, with superior being higher than inferior ones at early filling stage and smaller at later stage. In floret‐removal treatment, the activities of ADPG‐PPase, SSS, and SBE in superior grains of Xiushui 994 decreased at early filling stage and increased at middle or later stages. Meanwhile, the activities of SSS and SBE in both kinds of grains at early filling stage, and of ADPG‐PPase and granule‐bound starch synthase (GBSS) in inferior grains over the whole stage were increased. In leaf‐deleting treatment, the activities of ADPG‐PPase and SBE at early filling stage and GBSS at later filling stage were reduced in superior grains, while SSS activity at middle filling stage and SBE activity at later stage were increased.