氮素营养对马铃薯产量形成特性及品质的影响

为优化旱作马铃薯氮素施用量,进一步提高马铃薯产量和改善薯块品质,通过盆栽种植方式,研究氮素营养对马铃薯干物质积累量、根冠比、产量及薯块品质的影响。结果表明:施氮量为190 kg/hm~2时,马铃薯各生育时期干物质积累量、根冠比和单株产量最高,根据一元二次拟合方程得出最佳施氮量为206.39 kg/hm~2,此时马铃薯单株产量为388.22 g,与实际最佳施氮量接近;马铃薯薯块淀粉和VC含量均在施氮量为190 kg/hm~2时最高,薯块蛋白质含量随氮素的增加呈递增趋势,而有机酸含量随氮素增加呈先增后降的趋势,在施氮量为350 kg/hm~2时达到最大值。在试验条件下,综合分析马铃薯产量形成特性及各品质指标,马铃薯氮素最适施用量为190~206.39 kg/hm~2。     

Level and Timing of Nitrogen Fertilizer Application to Early and Semi-early Potatoes (Solanum tuberosum L.) Grown with Irrigation on Light Soils in Norway

Trials were performed with early and semi-early potatoes to test the effects of nitrogen (N) fertilizer level (0-160 kg N ha^-1) and timing (all at planting versus half then and half either soon after emergence or 3 weeks later). All seven trials with earlies were irrigated as required, whilst different irrigation regimes (moderate versus intensive) were compared in two trials with semi-earlies. No benefit was derived from splitting the N application. Haulm growth and N uptake increased in all cases almost linearly up to the highest N level, but tuber yield did not respond in the same way. The optimum N level was 80 kg N ha^-1 for a yield of 15 Mg ha^-1, rising to 120 kg N ha^-1 for a yield of 40 Mg ha^-1. Tuber quality was lowered by the use of excess N fertilizer, particularly in the case of earlies. The quantity of mineralised N present in the soil after harvest rose sharply with above optimum fertilizer use, and the amount of N present in crop residues also increased. The likely leaching after early potatoes was estimated to be up to 80 kg N ha^-1. The proportion of fertilizer N which was not accounted for in either tuber yield, crop residues or mineral N in soil was 26% in earlies and 38% in semi-earlies.     

马铃薯花色苷研究进展

综述了马铃薯花色苷的分布、种类、结构、提取纯化方法、生理功能和应用等方面的研究进展,并介绍了块茎在发育和储藏期间花色苷的变化及光、温等外界因素对马铃薯块茎颜色的影响.     

Impact of high temperatures on the marketable tuber yield and related traits of potato

A rapid warming of 2.8–5.3 °C by the end of this century is expected in South Korea. Considering the current temperature during the spring potato growing season (emergence to harvest; ca. 18 °C), which is near the upper limit of the optimum temperature for potato yield, the anticipated warming will adversely affect potato production in South Korea. The present study assessed the impact of high temperature on the marketable tuber yield and related traits of cv. Superior (which makes up 71% of the annual potato production in South Korea) in four temperature-controlled plastic houses and an outdoor field (37.27°N, 126.99°E) during 2015–2016. The target temperatures of the four plastic houses were set to ambient (AT), AT+1.5 °C, AT+3.0 °C, and AT+5.0 °C. The marketable tuber yield was significantly reduced by 11% per 1 °C increase over a temperature range of 19.1–27.7 °C. The negative impact of high temperature was associated not only with the yield loss of total tubers, which was mostly explained by the slower tuber bulking rate, but also the reduced marketable tuber ratio under temperatures above 23 °C, which was mainly attributed to the reduced number of marketable tubers (r = 0.79***). Under moderate temperatures below 23 °C, the source limited the number of marketable tubers without reducing the marketable tuber ratio. In contrast, the number of marketable tubers was limited by the marketable tuber set at the early growth stage rather than the source under the higher temperatures, which resulted in the reduction in the marketable tuber ratio below 56%. These results suggest that the objectives of breeding and agronomic management for adapting to the rapid warming in South Korea should include maintaining the ability to form tubers at the early growth stage under high temperatures, as well as the photosynthetic capacity and sink strength of the tubers.     

木薯试管微型薯与田间块根的结构发育比较

以华南8号木薯(Manihot esculenta Crantz cv.South China 8)无菌苗嫩茎为材料,采用植物组织培养方法获得试管微型薯,利用组织解剖学及组织化学方法研究木薯试管微块根(微型薯)的形态结构发育以及田间木薯块根形态结构发育,结果表明:木薯在组培条件下形成的微型薯没有次生结构的分化,微型薯的膨大在结构上表现为初生根皮层细胞体积的增大以及细胞间隙的增加。而田间块根的膨大在结构上表现为次生结构的产生以及大量淀粉的积累;组培微型薯和田间块根淀粉积累相比,存在时间上和空间上的差异,早期生长的微型薯没有淀粉的积累,生长5~10 d后在皮层薄壁细胞可见淀粉粒分布。而田间生长的木薯块根的淀粉是在初生根产生次生结构后就开始积累,淀粉主要积累在次生木质部,少部分分布于皮层薄壁细胞和韧皮部。     

块菌资源多样性及其地理分布

2　我国主要块菌的形态比较印度块菌 (Ｔ .ｉｎｄｉｃｕｍ :该菌子囊果与黑孢块菌极为相似 ,一般不易区别 ,仅可通过显微镜对产孢组织 (ｇｌｅｂａ)及子囊孢子壁文饰 (ａｓｃｏｓｐｏｒｅｗａｌｌｏｒｎａｍｅｎｔａｔｉｏｎ)结构上的差异进行分别。印度块菌子囊孢子数目通常多     

氮磷钾肥对马铃薯营养状况及块茎产量的影响

试验分别在甘肃省景泰县、内蒙古自治区达拉特旗和河北省沽源县3个马铃薯生产基地进行,在基地常规N、P2O5、K2O肥施用量分别为300、345、375kg/hm2的基础上,研究改变磷、钾、氮肥用量对马铃薯营养状况、块茎产量以及土壤养分的影响。试验结果表明,氮、磷、钾肥用量分别从N300、P2O5345、K2O375kg/hm2降低到180、180、225kg/hm2,对植株干物质累积量没有显著影响,3个基地都呈相同的趋势;3个基地不同处理的块茎产量也没有显著性差异。因此,在试验条件下,氮、磷、钾肥用量和比例为180-180-225的施肥处理,其经济效益较高。施肥对土壤养分含量有较大的影响,特别是磷肥,当施用磷肥后,土壤速效磷含量显著提高,而且主要存在于表层土壤(0￣20cm),这说明缺磷土壤通过施用磷肥,可提高土壤有效磷水平。     

温度对马铃薯块茎形成膨大的影响

 本试验采用"771—56"(早中熟)和"疫不加"(中晚熟)两个品种,分春、秋作,共6个播种期研究马铃薯块茎形成膨大对温度的反应。结果表明:马铃薯各生育期的长短都需要一定的度·日温度积累。播期不同显著影响匐匍茎形成和块茎形成的早迟,但不影响度·日数的变化,品种和季节不同,度·日数也不同。块茎形成不仅要求一定的度·日温度,而且要在一定的温度(16℃左右)条件下,块茎膨大的适宜温度为14～22℃,而最适温度为17～19℃。     

三种薯类作物对土壤干旱反应的差异

对甘薯、马铃薯、菊芋在土壤干旱下的一些生理反应作了比较研究。结果表明,在同样干旱程度下,甘薯的RWC、叶水势变化很小,叶片还保持一定的生长速率,叶细胞膜透性小,Pro没有积累或积累很少,品种间有一定差异;菊芋在干旱下表现则相反,RWC、叶水势剧烈下降、生长停止以至死亡,叶片细胞膜透性和Pro线性增加;马铃薯的各种参数变化处于二者之间。据此可以认为,甘薯的抗旱性最强,马铃薯次之,菊芋最弱。     

木薯块根总RNA提取方法的比较和改进

[目的]为更好地利用基因操作手段改良木薯品质和提取高质量的木薯总RNA提供科学依据。[方法]采用4种方法提取木薯块根RNA,筛选一种最简单、有效的方法,并利用RT-PCR技术克隆木薯淀粉分支酶,分析所提取RNA的质量。[结果]结果表明,用改进的CTAB法和plant RNAReagent kit均能提取高质量的RNA,用plant RNAReagent更能节省时间,而且纯度比较高。对plant RNAReagent提取的RNA进行RT-PCR克隆,克隆出了与木薯淀粉合成有关的SBEII基因。[结论]plant RNAReagent kit提取的RNA,其质量可以满足基本的试验要求。