Influence of the Indoleacetic Acid-Lysine Synthetase Gene (iaaL) of Pseudomonas syringae subsp. savastanoi on Yield Attributes of Potatoes

The iaaL gene of Pseudomonas syringae subsp. savastanoi encodes an indoleacetic acid-lysine synthetase which conjugates free indoleacetic acid (IAA) with lysine. lAA-lys is biologically less active than free IAA. The iaaL coding region was expressed under the control of the cauliflower mosaic virus 35S promoter and transgenic potato plants were produced (Spena et al. 1991). 35S iaaL potato plants are characterized by increased internodal length and epinastic bending of older leaves. In three greenhouse experiments with plants grown in pots of different size and in two growth chamber experiments tuber number increased in iaaL transgenic plants compared to untransformed and vector-transformed controls of the same genotype. The increase in tuber numbers observed under controlled conditions was reflected in tuber yield which increased in the pot grown transgenics.     

基于侯选基因标记的四倍体马铃薯休眠QTL关联分析

休眠期是马铃薯(SolanumtuberosumL.)重要的块茎性状之一,寻找调控马铃薯块茎休眠的关键基因,揭示其分子机制以选育具有适宜休眠期长度的马铃薯品种,对于解决当前马铃薯产业中过长或过短休眠期带来的经济损失和食品安全隐患等问题十分关键。前期研究在二倍体马铃薯连锁群体中定位了6个加性休眠QTL,本研究拟在四倍体马铃薯育种材料中验证这些休眠QTL。基于休眠QTL连锁的候选基因标记,采用混合线性模型(MLM),模型中考虑群体结构和亲缘关系(Q+K),在四倍体马铃薯自然群体St-hzau中对马铃薯块茎休眠期进行了关联分析。5号染色体上休眠QTL DorB5.3连锁的候选基因标记S199₃00和GWD (根据葡聚糖水双激酶α-glucan water dikinase基因设计)与马铃薯块茎休眠期具有显著的关联(P<0.05),分别解释了休眠期表型变异的7.8%和3.2%,分别能增加休眠期7.1 d和4.5 d,即在二倍体马铃薯连锁群体中定位的稳定主效休眠QTL DorB5.3在四倍体马铃薯关联群体St-hzau中也表现显著, DorB5.3的稳定性在关联分析结...     

芦荟蒽醌类物质对紫外线照射下洋葱和大蒜根尖细胞分裂的影响

以大蒜和洋葱为试材,研究了用波长为308nm的UV-B辐射灯照射,不涂抹芦荟蒽醌类物质;先涂抹芦荟蒽醌类物质,再进行UV-B照射;先进行UV-B照射,然后再涂抹芦荟蒽醌类物质,通过根尖压片法观察根尖细胞分裂过程等方式下洋葱和大蒜根尖细胞分裂的影响,根尖在自然条件下生长,不经UV-B辐射灯照射为对照(CK).结果表明:经紫外线照射过的洋葱和大蒜根尖细胞中出现了畸形核、染色体桥、落后染色体、游离染色体等异常现象.但先涂抹芦荟蒽醌类物质,然后进行UV-B照射的一组,根尖细胞中的异常现象明显减少.说明芦荟叶中的蒽醌类等次生代谢物质有屏蔽紫外线辐射、防止紫外线辐射伤害的功能.     

勺夹式藠头排种器设计与试验

针对藠头（Allium chinense）种植劳动强度大、人工成本高等问题,该研究设计了一种由排种盘、取种勺、取投种凸轮、种箱、安装板等组成的勺夹式藠头排种器。对该排种器工作原理和取种、携种、投种过程进行理论分析,建立离散元仿真模型,对取种过程进行仿真分析,确定了最优种勺结构。以大叶藠为对象,以取种合格率和漏取率为试验指标,进行种勺直径、种勺深度、取种起始角、种面高度与种箱高度之比和取种速度5因素显著性筛选试验,并以种勺直径、取种起始角、种面高度与种箱高度之比为试验因素进行回归正交试验;采用Plackett-Burman试验法和Box-Behnken中心试验法建立取种合格率和漏取率的回归模型,并进行参数优化,获得最优参数组合为种勺直径27 mm、取种起始角30°和种面高度与种箱高度之比92.5%。在最优参数组合下进行台架试验,得到取种合格率91.17%,漏取率6.17%。田间试验结果表明在前进速度0.1～0.2 m/s的条件下,该排种器平均播种合格率、平均重播率和漏播率分别为63.10%、12.76%和24.14%。研究结果可为藠头播种机械的研究与设计提供参考。     

大蒜精油对灰茶尺蠖的室内毒力及田间防效

采用大蒜精油对灰荼尺蠖进行了室内及田间药效试验,结果表明大蒜精油对灰茶尺蠖的致死中浓度(LC50)为1038.60 mg/L,50％大蒜精油100～250倍液对灰荼尺蠖低龄幼虫具有良好的速效性和持效性,建议生产中可在灰茶尺蠖1～2龄幼虫发生期喷施100～250倍液大蒜精油.这一结果为开发大蒜精油作为茶树主要害虫的新型低...     

Iodine Fortification Plant Screening Process and Accumulation in Tomato Fruits and Potato Tubers

Iodine is an essential microelement for human health, and the recommended daily allowance (RDA) of such element should range from 40 to 200 μg day^?1. Because of the low iodine contents in vegetables, cereals, and many other foods, iodine deficiency disorder (IDD) is one of the most widespread nutrient-deficiency diseases in the world. Therefore, investigations of I uptake in plants with the aim of fortifying them can help reach the important health and social objective of IDD elimination. This study was conducted to determine the effects of the absorption of iodine from two different chemical forms—potassium iodide (I^?) and potassium iodate (IO^? ₃)—in a wide range of wild and cultivated plant species. Pot plants were irrigated with different concentrations of I^? or IO^? ₃, namely 0.05% and 0.1% (w/v) I^? and 0.05%, 0.1%, 0.2%, and 0.5% (w/v) IO^? ₃. Inhibiting effects on plant growth were observed after adding these amounts of iodine to the irrigation water. Plants were able to tolerate high levels of iodine as IO^? ₃ better than I^? in the root environment. Among cultivated species, barley (Hordeum vulgare L.) showed the lowest biomass reductions due to iodine toxicity and maize (Zea mays L.) together with tobacco (Nicotiana tabacum L.) showed the greatest. After the screening, cultivated tomato and potato were shown to be good targets for a fortification-rate study among the species screened. When fed with 0.05% iodine salts, potato (Solanum tuberosum L.) tubers and tomato (Solanum lycopersicum L.) fruits absorbed iodine up to 272 and 527 μg/100 g fresh weight (FW) from IO^? ₃ and 1,875 and 3,900 μg/100 g FW from I^?. These uptake levels were well more than the RDA of 150 μg day^?1 for adults. Moreover, the agronomic efficiency of iodine accumulation of potato tubers and tomato fruits was calculated. Both plant organs showed greater accumulation efficiency for given units of iodine from iodide than from iodate. This accumulation efficiency decreased in both potato tubers and tomato fruits at iodine concentrations greater than 0.05% for iodide and at respectively 0.2% and 0.1% for iodate. On the basis of the uptake curve, it was finally possible to calculate the doses of supply in the irrigation water of iodine as iodate (0.028% for potato and 0.014% for tomato) as well as of iodide (0.004% for potato and 0.002% for tomato) to reach the 150 μg day^?1 RDA for adults in 100 g of such vegetables, to efficiently control IDD, although these results still need to be validated.     

小根蒜提取物对香椿保鲜效果的影响

通过测定Vc、叶绿素含量变化并结合外观变化,研究了小根蒜提取物对香椿保鲜效果的影响。结果表明：小根蒜提取物对香椿具有显著的保鲜效果,可以延长保鲜期7天以上。小根蒜水提物可以显著降低香椿的腐烂率,抑制Vc含量的下降,贮藏28天香椿的完好率仍维持在89.6%,Vc保持率为49.4%。小根蒜醇提物与6-BA复配可有效降低香椿的脱叶率和失重率,延缓叶绿素的降解,贮藏28天脱叶率为20.3%,失重率和叶绿素损失率分别为3.8%和5.3%。以小根蒜提取物作为天然蔬菜保鲜剂具有巨大的开发潜力。     

磷酰胺除草剂APM诱导洋葱根尖分生组织细胞异常有丝分裂和蛋白质组分变化

研究了不同浓度APM(4～6 μmol/L)和不同处理时间(4～6 h)对洋葱根尖细胞有丝分裂的影响.结果表明,当用5.6 μmol/L APM处理洋葱分生组织16 h后,中期细胞有丝分裂指数(Met.Ⅰ)从0.8(对照)分别提高至5.0、5.2.结果也同时表明,当APM浓度超过4 μmol/L时,严重影响细胞有丝分裂.在根尖细胞中,多极分裂细胞(尤其是3～4级),中期染色     

Isolation and characteristics of eight novel polymorphic microsatellite loci from the genome of garlic (Allium sativum L.)

Here we characterized eight novel polymorphic SSR markers, developed from an enriched genomic library of garlic (Allium sativum L.). These SSRs produced a total of 64 alleles across 90 garlic accessions, with an average of 8 alleles per locus. Values for observed (H_O) and expected (H_E) heterozygosity ranged from 0.16 to 0.77 (mean = 0.44) and from 0.22 to 0.86 (mean = 0.65), respectively. Six loci deviated significantly (P < 0.05) from Hardy–Weinberg equilibrium (HWE). The averages of gene diversity and PIC values were 0.65 and 0.62, respectively. The mean genetic similarity coefficient was 0.4380, indicating that among garlic accessions existed wide genetic variation. Based on 64 alleles obtained by 8 SSRs, a phenogram was constructed to understand the relationships among the 90 accessions. These newly developed SSRs should prove very useful tools for genotypes identification, assessment of genetic diversity and population structure in garlic.