Field experiments were conducted to study genotypic variation for potassium uptake and utilization efficiency in sweet potato for 2 years. In 1997, a field experiment was conducted using 84 genotypes under no potassium fertilization. In 1998, two field experiments were carried out. In experiment I, eight good genotypes evaluated from the previous experiment were tested at two K application levels: 0 and 270 kg ha-1 of K2SO4. In experiment II, three special varieties with respect to pigment content were tested at five K levels from 0 to 600 kg ha-1. A split-plot design with three replications was used. Variation existed among genotypes in K concentration, accumulation and potassium efficiency ratio(KER) in the field. Among various plant parts, petiole contained the highest K concentration and storage roots had the highest K accumulation at maturity. These changed considerably with genotype and K level. KER had significant positive correlation with root weight per plant, root: top ratio and harvest index (HI); and significantly negative correlation with K concentration and accumulation in the roots or whole plant at maturity. Based on KER, genotypes were identified as efficient and inefficient in potassium utilization. Yield increased generally in all genotypes with K application. The increase, however, varied among different genotypes. It was also found from this study that the fertilizer level that gave the highest yield was K2 which is 300 kg ha-1 of K2SO4. The yield increase as a result of K application was mainly due to the increase in root: top ratio which led to greater amount of photosynthate translocation to the storage roots causing their increase in size. Most of the quality parameters tested increased with increasing levels of K nutrition. Root dry matter(%), Brix (%), carotene content, anthocyanin content increased with K application. The extent of increase, however, differed with genotypes. Protein cntent generally tended to reduce with increase in K level. The degree of reduction also varied with genotypes.

采用扫描电镜、X-射线衍射和粘度测定等方法对甘薯、马铃薯和芋艿3种我国主要根茎作物淀粉的理化特性和糊化特性进行了研究，以便为其有效利用提供理论依据。结果表明：这3种根茎作物淀粉粒均有圆形、椭圆形和不规则多边形的形状，淀粉粒大小、分布、表面结构、晶体特性、淀粉成分和糊化特性作物间存在显著差异。而作物品种问差异较小。

运用差示扫描量热分析仪(DSC) 和淀粉黏度速测仪(RVA) 分析了8 个高色素甘薯品种淀粉糊化特性的差异。结果发现:品种间直链淀粉含量存在一定差异,变幅为19.59 %～25.46%;DSC 分析所得糊化温度也表现一定差异,起始温度( To ) 、峰值温度( Tp ) 和终止温度( Tc ) 的变幅分别为59.84～70.87 ℃、69.73～78.20 ℃和79.85～83.62 ℃,糊化时热焓变化(ΔH) 的波动范围为11.70～13.83 J/g ;甘薯淀粉的RVA 谱具有较高的最高黏度和明显的崩解值,且最终黏度低于最高黏度,不同品种的RVA 谱差异明显,主要表现在各个黏滞性特征值上,其中热浆黏度(HV) 和最终黏度(FV) 的品种间差异较大。相关分析表明,直链淀粉含量与糊化特征值间的相关性均未达到显著水平,而Tp与To、Tp与Tc、Tp与ΔH、Tp与PV、Tp 与HV、Tp 与FV 间均存在显著正相关,说明Tp 是衡量甘薯淀粉糊化特性的重要参数。

为探明甘薯维生素C 和胡萝卜素含量的基因型与环境效应,精选11 个有代表性的甘薯品种(系) ,分别在5 个产地进行多品种多试点有重复的品质稳定性研究。结果表明,在随机效应中,甘薯维生素C 的试点效应最为明显,而胡萝卜素则以基因型与试点互作效应最为明显。这表明需针对甘薯不同品质特点筛选和确定不同品种所适宜种植的地区,或不同地区所适宜种植的品种,以实现优质品种优质生产目的。

采用差示扫描量热分析仪（DSC）和淀粉粘度速测仪（RVA）分析了3 个甘薯品种（系）在块根发育过程中淀粉糊化特性的变化。结果表明，随甘薯生育期的延长，3 个品种的淀粉率都呈下降趋势，但直链淀粉率的变化则因品种而异。早期收获，徐薯18 和浙大9201 的直链淀粉率表现较高，而浙3449 则较低。随生育期延长，DSC糊化峰向低温方向移动，且峰宽增大、峰逐渐消失，其糊化温度和热焓变化也随之递减，而RVA 的最高粘度则呈现递增趋势。相关分析发现，甘薯直链淀粉含量与各糊化特性参数间存在一定相关性，但这种相关性的大小又受到品种制约。