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21.
本文在分析重庆市红苕生产现状及存在的主要问题的基础上,对2000年红苕生产发展前景进行了预测,提出了达到预测指标的途径和措施。 相似文献
22.
圆叶牵牛是成功入侵的一种外来杂草。植物的化感作用在外来杂草入侵中发挥着重要的作用。采用生物测定法研究了圆叶牵牛水浸提液对4个白菜品种种子萌发和幼苗生长的影响。结果表明:不同含量的浸提液影响白菜种子萌发的速率,低含量(1%、2.5%)的浸提液促进白菜丰抗78、津绿75的发芽,抑制率为-12.4%~-1.1%,但随着含量的提高,浸提液产生抑制作用,且逐渐增强,抑制率为9.7%~27.2%;不同含量的浸提液均能抑制西由78、早熟5号的发芽。浸提液均能抑制白菜根的生长,抑制率为12.5%~77.4%。低、中含量(1%~7.5%)的浸提液促进株高增加,抑制率为-47.4%~-5.3%,随着浸提液含量的升高,促进作用减弱并转为抑制作用,抑制率为9.10%~31.60%。综合分析,圆叶牵牛浸提液抑制白菜幼苗的生长发育,继而影响最终产量。从综合效应值来看,早熟5号受影响较小,是抗性最好的品种。 相似文献
23.
以红薯[Ipomoea batatas(L.) Lam]茎叶为原料,采用酶-超声波提取绿原酸.对料液比、加酶量、超声功率和超声时间进行了单因素和正交试验.确定绿原酸提取的最佳工艺为料液比1∶20、加酶量1.5%、超声波功率175W、提取时间20 min,在此条件下,绿原酸的提取率为3.45%. 相似文献
24.
用响应面法优化甘薯(Ipomoea batatas)叶黄酮的微波提取工艺,研究了微波功率、微波时间、乙醇体积分数、液固比4个因素对黄酮提取率的影响.并采用Box-Behnken设计对最佳提取工艺进行了优化.结果表明,最佳工艺条件为微波功率200 W、微波时间4 min、乙醇体积分数50%、液固比43∶1(V/m,mL∶g),在此条件下甘薯叶黄酮的提取率为8.082 7%,与预测值8.314 2%基本吻合. 相似文献
25.
Although preference for NH4+, NO3? or a combination of the two often differs among species, we know little about the responses of invasive plants to different inorganic N forms. Furthermore, many studies have suggested that an increase in N availability may facilitate further invasions. However, most of these studies predicted the positive feedback without considering the preference for N forms of invasive plants. Therefore, we cultivated four common invasive species (Mikania micrantha, Ipomoea cairica, Wedelia trilobata and Bidens pilosa) in South China with hydroponic media containing different forms of N (i.e. NO3?, NH4NO3 and NH4+) at equimolar concentrations. Our results showed that the N forms significantly affected the growth, biomass allocation and physiological traits of the plants. All four invasive plants supplied with NO3? alone had better performance and greater allocation to root biomass than did plants that were supplied with NH4+ alone. Moreover, the photosynthetic rate, pigment content and photosystem II activity of plants supplied with NO3? or NH4NO3 were significantly higher than those of plants supplied with NH4+alone. The results suggested that all four invasive plants preferred NO3? rather than NH4+, and changes in NO3? played an important role in furthering the invasions of these plants than did changes in NH4+. Our results implied that decreasing NO3? may be a useful tool for controlling and managing invasive plants preferring NO3?. In addition, this study highlighted the importance of considering plant N form preference to better understand plant invasions. 相似文献
26.
甘薯基因组NBS-LRR类抗病家族基因挖掘与分析 总被引:1,自引:0,他引:1
HUANG Xiao-Fang BI Chu-Yun SHI Yuan-Yuan HU Yun-Zhuo ZHOU Li-Xiang LIANG Cai-Xiao HUANG Bi-Fang XU Ming LIN Shi-Qiang CHEN Xuan-Yang 《作物学报》2020,46(8):1195-1207
NBS-LRR类基因家族是植物抗病R基因(Resistance gene)数量最多的一类,具有NBS (Nucleotide-binding site)和LRR (Leucine-leucine-repeat)结构域。甘薯(Ipomoea batatas)栽培种基因组已完成测序,但尚未注释,本研究对甘薯基因组序列进行外显子预测,得到甘薯染色体组全基因组蛋白序列,在此基础上进一步对NBS-LRR家族基因鉴定和分析表明,甘薯基因组中含有379个NBS-LRR家族基因,占全基因组基因总数的0.212%,其中N型亚家族120个,NL型103个, CNL型133个, TNL型22个, PN型1个。所有染色体上均有NBS-LRR家族基因分布,但数量明显不同,其中有60.9%的NBS-LRR基因序列呈簇状分布。NBS-LRR基因序列有15个保守结构域,在N端较为保守。研究结果为甘薯进一步开展NBS-LRR家族基因的功能研究和抗性育种提供了参考。 相似文献
27.
28.
Genetic variation of sweet potatoes (Ipomoea batatas L.) cultivated in Chile determined by RAPDs 总被引:1,自引:0,他引:1
Boris Sagredo Patricio Hinrichsen Horacio López Alberto Cubillos Carlos Muñoz 《Euphytica》1998,101(2):193-198
RAPD (randomly amplified polymorphic DNA) technology was applied to analyze the genetic variability of sweet potato germplasm
existing in Chile and elsewhere. Analysis of 28 cultivars from all over the world showed polymorphic bands with all 18 primers
tested. A total of 124 RAPD bands were scored with an average of 6.9 polymorphic bands per primer. These results confirm that
sweet potato exhibits high genetic variation. Two groups were distinguished: one containing Peruvian cultivars, and another
containing cultivars from the rest of the world. Analysis of 14 accessions from Central Chile and one from Northern Chile
showed polymorphic bands with 24 of 26 primers tested, but almost all of the 140 polymorphic bands merely showed the distinctness
of the Northern accession. The almost complete uniformity of the other 14 accessions shows that sweet potato germplasm collected
in Central Chile has very little genetic variability and may be derived from a single cultivar.
Based on these results and on historical records, some hypotheses are proposed to explain the origin of sweet potatoes cultivated
in Chile.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
29.
30.
A study compared the spread of sweet potato virus disease (SPVD) into crops of two moderately resistant and initially SPVD-free sweet potato cultivars in northern and southern Mpigi, Uganda. Whiteflies, the vector of sweet potato chlorotic stunt crini virus (SPCSV), a component cause of SPVD, were similarly abundant in farmers' sweet potato fields around Namulonge in northern Mpigi, and Kanoni in southern Mpigi. However, mean incidence of SPVD in farmers' crops neighbouring the trials was higher at Kanoni (13.3%) than at Namulonge (2.8%). Furthermore, spread of SPVD into initially SPVD-free sweet potato plots of two only moderately resistant cultivars was greater in plots at Kanoni than in plots at Namulonge. The SPVD-resistant New Kawogo was the most common cultivar grown in farmers' fields at Namulonge and had few diseased plants, whereas susceptible cultivars with relatively high incidences of disease predominated at Kanoni. Final SPVD incidence in each trial was positively correlated with a measure combining the proximity and level of inoculum in surrounding fields. The study demonstrates the importance of local SPVD inoculum in determining the rate of spread of the disease into fields and implies that the widespread cultivation of a resistant variety limits infection of susceptible cultivars grown nearby. 相似文献