The growth and the respiration in roots of sweet potato plants under a moderate potassium deficiency

A seven days' culture of sweet potato plants under a deficient potassium application induced various metabolic disturbances in the roots (1,2) and the leaves (3). Prolonged cultures of taro (4), broad bean plants (5), and barley (5) suggested that a half level of the normal potassium content in roots might be a critical point of K -deficiency resulting in a higher respiration rate than its normal status. Such a temporary enhancement of respiration accompanied by accumulation of amino-N and reducing sugars may not necessarily contribute to the accumulation and the assimilation of salts, but accelerate the disturbance of plant metabolism to cause early death of the tissues. This work deals with supplemental data on the effects of K -deficiency on the plant growth and the respiration in roots, comparing these effects in a 15 days' culture of sweet potato plants with those in a longer term culture of other plant species (4,5).     

Effect of mineral nutrition on metabolic change induced in crop plant roots (V)

In the previous work concerning the effect of potassium nutrition on glycolysis in sweet potato roots (1), monoiodoacetic acid (MIA) and sodium fluoride (NaF) inhibited more strongly respiration in younger roots and root tip parts, and yet a potassium deficiency enhanced its inhibition. The inhibition of MIA, which inhibits triose phosphate dehydrogenase (2), may indicate the importance of the EMP pathway and the Krebs cycle (3,4). The inhibition of NaF, which in higher concentrations inhibits enolase (2), may suggest the importance of the metabolism following phosphoglycerate → phosphoenolpyruvate or the Krebs cycle (3,4). It is of interest, therefore, to elucidate the role of the Krebs cycle in respiration in sweet potato roots, and what significance potassium nutrition has in the Krebs cycle operation. This paper deals with experiments bearing on respiration in roots of sweet potato plants grown at varying degrees of potassium application, especially in the presence of various inhibitors and / or substrates.     

Effects of potassium nutrition on the glycolysis and the krebs cycle in taro plants

The previous works (1, 2) with the bleeding sap from taro plants showed that a potassium deficiency altered the amplitude and the period of the diurnal periodicity in exudation process with the roots, and suggested that potassium might be an essential element for an intensive exchange of amino acids between living xylem tissues and xylem sap. The other works (3,4) with excised roots from sweet potato plants grown in a seven days solution culture showed that the relatively K-deficient roots had higher respiratory activities than the normal, especially In the root tip, and accumulated concomitantly higher levels of reducing sugars and amino nitrogen. Recently, however, an increasing number of works (5, 6) has been devoted exclusively to elucidating the relationship between respiratory activity in plant tissues and organic acid metabolism under a relative K-deficiency. In this work the effects of potassium nutrition on the glycolysis and the Krebs cycle in the roots and the leaves of taro plants are investigated in an attempt to compare these effects in a longer term culture of taro plants with those in a seven days culture of sweet potato plants.     

钾素对食用型甘薯糖代谢相关酶活性的影响

为了探讨钾素提高甘薯块根可溶性糖含量的生理基础。选用典型的食用型甘薯品种北京553,设置不同施钾处理,于2009～2010年2个生长季在山东农业大学农学试验站进行试验。采用甘薯块根膨大过程中定期取样的方法,测定块根可溶性糖和淀粉含量及相关酶活性、功能叶蔗糖含量及相关酶活性。结果表明,与对照比较,施用钾肥能显著提高块根产量、可溶性糖及各糖组分含量,其中K2O用量为24 g/m2处理增幅最大,为最适用量。进一步研究发现,适宜供钾处理显著提高了功能叶磷酸蔗糖合成酶活性和蔗糖含量,生育期内平均增幅分别为10.31%和34.13%,同时提高了块根中蔗糖合成酶、不溶性酸性转化酶的活性,生育期内平均增幅为16.47%和3.66%,在提高源端光合产物供应的同时促进蔗糖在库端的卸载,促进块根中淀粉和可溶性糖的积累;适宜供钾处理还提高了块根中-和-淀粉酶的活性,生育期内平均增幅分别为26.06%和14.64%,促进淀粉向可溶性糖转化。此外,适宜供钾处理还显著提高了生长前期和后期块根中可溶性酸性转化酶活性、以及生长后期块根中蔗糖-蔗糖果糖基转移酶活性,促进了葡萄糖、果糖和果聚糖在块根中的积累。在甘薯收获期,块根可溶性糖和淀粉含量分别提高了13.52%和3.02%。即钾肥能够增加块根中蔗糖的供应量、促进块根对蔗糖的吸收、促进淀粉水解,是其提高块根可溶性糖含量的生理原因。     

干旱胁迫下钾素对甘薯碳水化合物及内源激素含量的影响

【目的】研究干旱胁迫下施钾量对不同生长时期甘薯碳水化合物及内源激素含量的影响,为甘薯的抗旱高产栽培提供理论依据。【方法】选用食用型甘薯品种‘泰中6号’为材料,以硫酸钾（K₂SO₄）为供试肥料,水分处理设土壤最大持水量的60%～70%和30%～40%,依次代表正常供水（W1）和干旱胁迫（W0）;钾肥设K0、K1、K2、K3四个水平,K₂O用量分别为0、120、240和360 kg/hm2。分析了不同生长时期甘薯干物质含量、淀粉和可溶性糖含量、内源激素含量及收获期块根产量。【结果】干旱胁迫下甘薯植株干物质含量、块根和淀粉产量显著降低,施钾有利于甘薯植株干物质含量的提高、块根的膨大和淀粉的生成和积累,甘薯植株和块根干物质含量、块根淀粉含量和积累量最大均为K2处理,较K0提高幅度最大分别达到31.7%、43.6%、10.6%和50.6%。相同钾用量条件下,干旱胁迫下块根单薯重显著高于正常灌水,单株结薯数显著低于正常灌水。正常灌水条件下施钾后甘薯叶片可溶性糖含量降低,而块根可溶性糖含量升高,干旱胁迫下施钾使甘薯叶片和块根可溶性糖含量增大,较K0提高幅度最高分别达到31.4%和36.0%。干旱胁迫下施钾后甘薯叶片和块根IAA、ABA、ZR和GA含量显著增大,较K0提高幅度最高分别达到12.7%、15.7%、12.0%、10.4%和21.4%、15.6%、65.7%、13.0%,促进了甘薯植株碳水化合物含量和干重的提高,块根淀粉积累速率增大。【结论】干旱胁迫下施钾促进了干物质向块根的分配,提高了甘薯块根单薯重,从而增加了单位面积甘薯块根产量。干旱胁迫下钾素提高甘薯块根和叶片内源激素（ABA、IAA、ZR、GA）含量,块根内源激素含量的增加促进了块根淀粉的合成和积累,叶片内源激素含量的增加促进了地上部茎叶生长、茎叶干物质积累和叶片可溶性糖含量的增加,增强了甘薯的抗旱性。     

甘薯抗疮痂病多胺与吲哚乙酸代谢的研究

研究不同抗性甘薯品种受疮痂病菌侵染前后多胺和吲哚乙酸代谢变化结果表明 ,感染疮痂病菌后抗病与感病品种甘薯叶片中吲哚乙酸含量和多胺氧化酶活性降低 ,多胺总量及腐胺含量增加 ,腐胺 / (精胺 亚精胺 )比值升高 ,感病品种变化幅度高于抗病品种。疮痂病菌侵入后感病品种甘薯叶片中绿原酸含量下降 ,吲哚乙酸氧化酶和过氧化物酶活性升高 ,而抗病品种则相反。     

Invertase inhibitors from sweet potato (Ipomoea batatas): purification and biochemical characterization

Two proteinaceous invertase inhibitors, designated ITI-L and ITI-R, were purified to electrophoretic homogeneity. ITI-L was purified from acetone powder of sweet potato leaves through sequential steps entailing buffer extraction, acid treatment, DEAE-Sephacel ion-exchange chromatography, and Sephacryl S-100 gel filtration. ITI-R was purified from sweet potato tuberous roots by sequentially applying buffer extraction, Con A-Sepharose affinity chromatography, DEAE-Sephacel ion-exchange chromatography, Sephacryl S-200, and Superose 12 gel filtration. The optimal pHs for interaction between ITI-L and ITI-R and acid invertase from sweet potato leaves were 5.5 and 5.0, respectively. The molecular masses of ITI-L and ITI-R were 10 and 22 kDa, respectively, as estimated by both gel filtration and SDS-PAGE. Both inhibitors were thermostable (90% of the activity remained after incubation at 100 degrees C for 20 min), and Western blotting showed them to be immunologically related.     

腐植酸钾对食用甘薯品种钾吸收、利用和块根产量的影响

甘薯属于喜钾作物,增施钾肥是提高甘薯块根产量的重要措施之一;而腐植酸具有促进作物生长、提高肥料利用率等作用。为探讨腐植酸与钾肥配合施用对食用甘薯钾吸收利用以及块根产量的影响,本研究利用自行制备的两种腐植酸钾肥料,选用食用甘薯品种“北京553”于2005年在山东农业大学农学试验站进行了研究。试验采用块根膨大过程定期取样和收获期测产相结合的方法,观察了块根膨大过程中植株地上部鲜重/块根鲜重（T/R）比值、叶片和块根含氮量/含钾量（N/K）比值以及块根膨大速率的变化及其与块根产量的关系,同时分析了钾素生产效率和钾肥利用率在处理之间的差异。结果表明,施用适量钾肥可以降低植株T/R比值以及叶片和块根的N/K比值,提高块根膨大速率,提高收获期生物产量及其干物质在块根中的分配率,增产24.18%。但是,施用钾肥降低了钾素生产干物质和块根的效率。施用适量腐植酸可以降低块根N/K比值,提高叶片N/K比值,提高块根膨大速率以及收获期的生物产量,增产5.70%。同时,施用腐植酸提高了钾素产干物质和块根的效率。与等量氧化钾对照比较,在块根膨大前、中期,施用腐植酸钾可以降低植株T/R比值以及叶片和块根的N/K比值,提高块根膨大速率;块根产量提高8.11%～9.50%。同时,腐植酸钾肥料的吸收利用率和农学利用率都显著提高。     

施钼对不同钼效率冬小麦叶片呼吸作用相关酶的影响

以冬小麦钼高效(97003)和钼低效(97014)品种为供试材料,采用土培方法,研究施钼对冬小麦分蘖期、拔节期、孕穗期和灌浆期功能叶多酚氧化酶(PPO)、抗坏血酸氧化酶(AAO)、乙醇酸氧化酶(GO)等呼吸作用相关酶类活性变化的影响。结果表明,施钼后,PPO活性在4个生育期均降低;AAO活性在分蘖期和拔节期降低,而在孕穗期和灌浆期上升;GO活性则在分蘖期、拔节期和孕穗期降低,而在灌浆期升高。钼对不同钼效率冬小麦叶片呼吸作用酶的影响存在着差异。施钼有利于促进冬小麦分蘖期和拔节期碳水化合物的积累,从而促进生物量的提高,而在孕穗期和灌浆期由于植株生长中心的转移,呼吸作用酶变化复杂。     

柿叶提取物对马铃薯多酚氧化酶的抑制作用

多酚氧化酶（PPO）是生物体内黑色素合成的关键酶。研究了甜柿叶乙醇提取物、涩柿叶乙醇提取物、甜柿叶水提取物、涩柿叶水提取物对马铃薯多酚氧化酶活性的抑制作用。结果表明,上述4种柿叶提取物对马铃薯多酚氧化酶具有明显的抑制作用,使该酶活力下降50％所需的浓度（IG50）分别为0．21、0．26、0．37、0．45mg／mL。乙醇提取物较水提取物的作用效果更强,甜柿叶提取物的抑制作用比涩柿叶提取物的强,4种柿叶提取物对酶的抑制作用均为非竞争性可逆抑制,其抑制常数（KI=KIS）分别为0．18、0．23、0．34、0．45mg／mL。     

湿度对甘薯愈伤的影响

为探索湿度对甘薯愈伤的影响,本试验以普薯32号甘薯为原料,人工模拟机械损伤后于25℃、不同相对湿度(RH50%和RH80%)条件下愈伤,通过比较甘薯木质素生成、失重率、呼吸强度、愈伤过程关键酶活性、总酚和类黄酮含量的差异,评价湿度对甘薯愈伤的影响。结果表明,RH80%条件下较RH50%更有利于甘薯愈伤木栓组织的形成,在愈伤4 d时甘薯木质素积累达到最高。与RH50%组相比,RH80%条件处理能显著提高甘薯愈伤组织苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)和多酚氧化酶(PPO)活性(P<0.05),提升总酚、类黄酮含量,促进呼吸高峰提前,降低甘薯重量损失。相关性分析表明,RH80%条件下愈伤,甘薯木质素含量与PAL、POD、PPO活性及总酚、类黄酮含量呈显著正相关(P<0.05)。本研究结果为甘薯采后愈伤提供了一定的理论依据。     

甘薯茎叶多酚分离纯化及降血糖活性研究进展

甘薯茎叶为甘薯地上蔓生部分,一年能多次采收,与甘薯块茎产量相当。甘薯茎叶中的多酚类物质含量丰富,主要为酚酸类和黄酮类物质,具有抗氧化、降血糖、抗菌消炎、抗肿瘤、保护肝脏和免疫调节等作用,且甘薯茎叶多酚类物质的降血糖作用已成为天然产物活性研究领域的热点之一。本文综述了甘薯茎叶多酚类物质的提取和分离纯化方法、酚酸类和黄酮类物质的组分构成及体外、体内降血糖活性作用,并展望了甘薯茎叶多酚类物质降血糖活性的研究方向,旨在为甘薯茎叶多酚类物质在食品和医疗保健领域的开发应用提供理论参考,提高甘薯茎叶多酚类物质的有效开发利用率,进一步促进我国甘薯茎叶加工业的可持续发展。     

Effects of Sodium on Potassium Nutrition in Three Tropical Root Crop Species

The potassium (K) nutrition and high K requirement of tropical root crops may be affected by their sodium (Na) status, as has been observed in a number of plant species. Solution culture was used to study the effects of K and Na supplies in tannia [Xanthosoma sagittifolium (L.) Schott.], sweet potato [Ipomoea batatas (L.) Lam.] and taro [Colocasia esculenta (L.) Schott]. At low K supply, Na ameliorated symptoms of K deficiency and increased growth in tannia, and to a lesser extent in sweet potato, but not in taro. None of the species responded to Na at adequate K supply. Differences in response to Na were attributed to differences in Na translocation to plant tops. At maximum Na supply, the Na concentration in index leaves averaged 1.82% in tannia, 0.205% in sweet potato, and 0.0067% in taro. An increase in the supply of Na resulted in a shift in the critical K concentration for deficiency (i.e., 90% of maximum yield) in index leaves from 2.9% to 1.2% in tannia, and from 4.8% to 2.5% in sweet potato. The critical K concentration in taro was 3.3%, irrespective of Na supply. To overcome the problem in tannia and sweet potato of determining the critical concentration relevant to a leaf sample of unknown K status, a relationship was established for each species relating the critical K concentration to the concentration of Na in the index leaves.     

低钾胁迫下不同钾效率甘薯的钾吸收利用规律研究

以钾高效品种徐薯28和低效品种济薯22为材料,采用室内土培试验研究了不同施钾量下,甘薯钾的积累与分配及利用规律。结果显示:不施钾显著促进甘薯地上部生长,抑制块根膨大,但品种间变幅不同,钾高效型徐薯28具有更强的根系膨大能力。徐薯28苗期地上部钾浓度显著高于济薯22,叶片和叶柄钾含量分别比济薯22高33.1%、33.9%;但收获期徐薯28植株钾含量为8.7 g/kg,显著低于济薯22的9.8 g/kg。施钾或不施钾下,收获期徐薯28钾分配系数分别为4.2、3.2,济薯22分别为2.0、1.5,表明徐薯28将钾更多分配到块根部分,而济薯22更多分配到茎叶部分。各处理的块根钾利用效率(KIUE-T)为65.1~135.9,施钾及不施钾下,徐薯28块根钾利用效率都显著高于对应的济薯22处理。甘薯植株内钾含量高低是决定济薯22及徐薯28钾利用效率高低的关键因素。因此,两甘薯基因型间钾的利用效率差异主要体现在:徐薯28即使在不施钾下,苗期地上部尤其是茎叶能维持较高的钾含量,为后期块根膨大奠定基础,而收获期维持较高的钾分配系数及植株较低的钾浓度,而济薯22则相反。     

高温胁迫下水稻氨基酸态氮与铵态氮营养效应研究

在高温胁迫无菌砂培条件下对无机氮 (硫酸铵 )、有机氮 (甘氨酸 ,谷氨酸和赖氨酸 )和缺氮 (对照 )培养的水稻植株干物重、总氮量及其根、叶谷草转氨酶 (GOT)和谷丙转氨酶 (GPT)活性作了研究。结果表明 ,有机、无机氮均被水稻吸收 ,且吸收量相当。低浓度无机氮 (N 10mg/L)或有机氮培养 2 0d后的水稻植株总氮量比对照的高 50%以上 ;无机氮培养的植株干物重显著低于有机氮培养和对照 ,表明植株受NH4+毒害。培养 15d后 ,多数有机氮培养的植株根或叶GOT或GPT活性显著高于对照 ,但根、叶间有较大差别 ;而无机氮培养的植株根GOT及根、叶GPT活性是对照的 2倍或以上。高浓度无机氮 (N 500mg/L)处理 6h后稻株根、叶GPT活性分别是对照的2.5和4倍 ,而高浓度甘氨酸 ,谷氨酸和赖氨酸态氮 (N 500mg /L)处理 6h后 ,根、叶GPT活性分别是对照的 5.7、9.4、1.9倍及1.8、2.3、1.4倍。     

Expression and characterization of sweet potato invertase in Pichia pastoris

An invertase cDNA (Ibbetafruct1) was cloned from sweet potato leaves and characterized. The deduced amino acid sequence of the Ibbetafruct1-encoded protein was closely related to vacuolar invertases and included the WECVD catalytic domain characteristic of them. An expression plasmid containing the coding region of Ibbetafruct1 under the control of the alcohol oxidase promoter was used to transform the methylotrophic yeast Pichia pastoris. The biochemical properties for the expressed recombinant enzyme, which was determined to be the acid beta-fructofuranosidase with an acidic pI value (5.1), were similar to those of vacuolar invertases purified from sweet potato. Periodic acid/Schiff staining and Con A-Sepharose gel-binding experiments revealed the recombinant invertase to be a glycoprotein containing glucose and/or mannose residues. Furthermore, the carbohydrate moiety appears to be a key determinant of the enzyme's sucrose hydrolysis activity, substrate affinity, and thermal stability.     

钙信号抑制剂加剧低钾胁迫对烟草幼苗光合特性及钾吸收的影响

  【目的】  研究低钾胁迫抑制钙信号传导对植株幼苗叶片光合特性及钾吸收的影响,为缓解作物的低钾胁迫提供理论依据。  【方法】  以烟草品种K326为试验材料进行了室内水培试验。烟草幼苗先在营养液正常钾(K+ 5 mmol/L)和缺钾(K+ 0.15 mmol/L)营养液中生长8 天,然后在营养液中分别施加钙通道有机阻断剂Vp、钙通道无机阻断剂LaCl₃和钙离子螯合剂(EGTA)钙信号抑制剂,继续生长4天后取样,测定植株干鲜重、电导率、活性氧含量、叶片抗氧化酶活性、叶片光合特性等指标和植株地上、地下部钾素浓度及钾离子吸收相关基因表达量。  【结果】  1)不添加钙通道抑制剂或螯合剂条件下,低钾胁迫的烟株地上部和根系干重较常钾水平显著降低了59.29%、39.82%,鲜重显著降低了51.58%、48.19%,除水汽压饱和亏外的其余5项光合特性指标显著降低,植株地上部和根系钾含量分别显著降低了39.31%和77.05%,而叶中可溶性蛋白、相对电导率、过氧化氢含量则显著增加,NKT2、NtKC1、NtHAK1、NtHAK5基因的相对表达量分别增加了2.09、3.32、3.23、12.34 倍。2)常钾水平下,3个钙抑制剂处理未明显影响地上部和根系干鲜重,而低钾水平下,钙抑制处理的地上部鲜重和干重显著高于无钙抑制剂对照。两个钾水平下,与各自对照相比,3个钙抑制剂处理的叶片相对电导率、活性氧积累量均显著增加,抗氧化酶SOD和POD活性、叶绿素含量显著减少,光合特性指标(除水汽压饱和亏外)明显降低。3)两个钾水平下,3个钙信号抑制剂处理的烟株地上部和根系钾含量均显著低于其对照,低钾胁迫下平均降低幅度分别达到25.54%和53.36%。低钾胁迫下,钾离子通道基因NKT2、NtKC1和转运蛋白基因NtHAK1、NtHAK5在根系中的相对表达量分别平均降低了60.60%、50.62%、38.61%、69.79%,钙通道相关基因NtCNGC1和NtCNGC11在根中的相对表达量分别平均降低了95.36%和87.04%。  【结论】  低钾胁迫明显影响烟株幼苗生长、光合作用及对钾素的吸收和积累。低钾水平下,外施钙通道抑制剂或螯合剂可进一步降低烟草叶片抗氧化酶活性,减弱烟株叶片光合作用,并抑制根中钾吸收相关基因的表达和烟株对钾素的吸收。     

钾通道ZmK2;1在水稻中超表达提升水稻氮素利用潜力

气孔运动与光合同化效率密切相关,通过影响叶片对碳源的获取能力对植株生长发育和籽粒生产发挥作用。针对稻田过量施氮导致的环境风险和氮素利用效率趋缓的现状,研究高氮投入时促进氮素吸收利用的调控策略非常必要。本研究利用气孔钾通道基因ZmK2;1超表达水稻遗传材料,设置N 缺乏(LN, 不施氮)、中量或减少氮投入(MN, 200 kg hm_^-2)和过量施氮(HN, 350 kg hm_^-2)三个施氮水平的田间试验,对ZmK2;1超表达植株在生育后期的氮素营养特征和生产特性进行研究。结果表明：ZmK2;1超表达能改善水稻植株在各氮肥施用水平下的产量形成特征,提升植株氮钾含量和生物量,改善植株的氮素营养特征,其剑叶在生育后期保持较高的光合效率和气孔导度。另外,ZmK2;1基因超表达能促进水稻氮素利用效率的提升,尤其在过量施氮(HN)条件下,该基因过表达仍能够改善其氮素利用。利用气孔钾通道ZmK2;1在水稻中超表达可以调节植株和关键功能叶氮钾比,促进各施氮水平下的光合效率的同时提升了水稻产量；在过量施氮时,依然能保持较高的光合同化能力,提升水稻氮素利用率和增产潜力。     

Synergistic effect of root-associated bacteria on plant growth and certain physiological parameters of banana plant (Musa acuminata)

Fifty strains of bacteria isolated from banana roots were studied for their plant growth promoting (PGP) activities. Indole -3- acetic acid (IAA) production by root-associated bacteria ranged from 20 to 302 µg ml^?1. Seventeen isolates (34%) were positive for siderophore production and 18 isolates (36%) showed phosphate solubilization. None of the isolates showed potassium solubilization. All the isolates showed growth on nitrogen free Jensen medium. Identification of the bacteria based on 16S rRNA gene sequencing revealed that the isolates belonged to genus Bacillus sp, Klebsiella sp, Microbacterium sp and Enterobacter sp. A pot experiment in a greenhouse was conducted to investigate the effect PGP bacteria on banana plant growth and enzyme activities. The results demonstrated a significant (P < 0.05) increase in plant growth, chlorophyll, total phenolics, proline, catalase and ascorbic acid oxidase in banana plants treated with PGP bacteria as compared to control. However, the plant-growth response was variable and dependent on the bacterial strains, enzyme activity, and growth parameter observed. The present study revealed that bacteria showing multiple PGP activity could be used as biostimulants in enhancing banana production.     

甘薯淀粉产量及相关性状的遗传多样性和关联度分析

甘薯[Ipomoea batatas(L.)Lam.]是加工淀粉和燃料乙醇的重要原料,是目前我国最具开发前景的非粮食类新型能源作物。选育高淀粉产量的能源型甘薯新品种是甘薯育种的重要目标。为了获得准确筛选高淀粉产量育种材料的性状指标,提高甘薯高淀粉产量育种效率,缩短育种周期,本研究利用不同甘薯品种(系)的自然变异,根据淀粉产量、不同生长发育阶段的5个主要农艺性状和3个淀粉合成关键酶活性测定结果,利用相似系数和遗传距离矩阵,以类平均法对国内48份不同淀粉产量甘薯种质资源进行了遗传多样性分析,通过关联度分析研究了淀粉产量与不同时期农艺性状、淀粉合成关键酶活性的相关性。结果表明:48份甘薯种质资源材料在不同时期农艺特征差异较大;不同时期农艺性状的聚类结果中,栽后100 d的农艺性状与淀粉产量关联度最大,淀粉产量与该时期的基部分枝数呈极显著负相关(r=0.428),与干率呈极显著正相关(r=0.423),而与最长蔓长、单株结薯数和单株鲜薯重相关性不显著。48份甘薯种质材料在不同时期的酶活聚类结果差异明显。不同时期的甘薯淀粉合成关键酶活性聚类结果中,栽后50 d酶活聚类与淀粉产量聚类结果关联度最大,淀粉产量与该时期测得的ADPG焦磷酸化酶(ADPG-PPase)活性呈负相关关系(r=0.163),与蔗糖合成酶(SS)活性(r=0.101)、蔗糖磷酸合成酶(SPS)活性(r=0.016)呈正相关,但相关性均未达到显著水平。加之淀粉合成关键酶活性测定步骤繁琐,不适宜作为甘薯高淀粉产量育种早期选择的生理指标。在高淀粉产量育种材料筛选时可于栽后100 d对农艺性状进行综合考察,重点考虑干率较高及分枝数较少的品系。本研究可为甘薯高淀粉产量育种提供一定的理论依据。