江苏位于茶树种植的北缘地区,茶树易受冻害.随着无性系茶树良种的不断推广,筛选抗寒性强、适宜江苏种植的茶树新品种,对茶树新品种推广具有重要意义.本演技利用极端低温气象条件,对引进和江苏自选的31个品种的幼龄茶树进行冻害调查试验,结合冻害指数的系统聚类分析,评估不同品种幼龄茶树的抗寒能力.试验结果表明,正常叶色的幼龄茶树除'川茶2号'外基本为轻中度冻害,其中'多抗香'、'锡茶5号'、'龙井43'、'龙井长叶'、'迎霜'、'舒茶早'等品种幼龄茶树抗寒性强.叶色变异茶树品种间抗寒性存在差异,白色叶幼龄茶树为轻度冻害,黄化叶和紫化叶茶树多为中重度冻害,其中'中白1号'、'白叶1号'、'中白4号'、'中黄2号'抗寒性强,'中黄1号'、'御金香'、'郁金香'抗寒性较强.

江苏横跨江南荼区和江北茶区,茶叶生产历史悠久.介绍了江苏省茶叶生产现状,分析了茶产业的特点与发展优势,提出了未来茶产业的发展趋势.

分析幼龄茶树与大豆、玉米间作及秸秆覆盖还田对土壤养分状况等的影响.结果表明,间作大豆、玉米及秸秆还田后均能够提高土壤pH值,缓解茶园的土壤酸化现象.开花期,间作不同品种大豆,土壤全磷、全钾、速效磷、速效钾、钙、镁、铝含量均高于对照,但土壤全氮含量变化不同;间作玉米土壤全氮含量降低,不利于幼龄茶树生长.秸秆还田后40 d,各处理土壤全磷、全钾、速效钾、钙、镁、铝含量均高于对照,但全氮、速效磷含量变化存在差异,通豆07-195和苏糯11号处理土壤全氮含量显著苏菜豆6号处理土壤速效磷含量,与对照无显著性差异.综合土壤pH值和养分变化情况,间作通豆6号更利于茶园土壤养分的改善,苏糯14号秸秆处理在还田后40 d对土壤改良作用最佳.

常州市是江苏省茶叶主产区之一,历史悠久.从产销情况、品种结构、技术水平、管理水平等多方面阐述了常州市茶叶发展现状,分析了常州市茶产业发展过程中存在的产品结构单一、良种化程度不高、机械化程度低等问题,提出相应的发展对策,以促进常州市茶产业健康稳定发展.

年宵花卉是指“元旦-春节”特定时段上市消费的花卉类别,是我国百姓文化消费的年货产品.近年来,全省年宵花消费由集团消费向大众消费转变、由大规格产品向小型精致化产品转变,促进全省设施花卉生产结构不断调整、产品不断创新、品质不断提升. 2019年江苏省年宵花产销基本情况 销量情况.今年江苏省年宵花卉产销平稳,产品销量上升,平均售价呈下降趋势.市场产品丰富,花大色艳的精美盆栽花卉仍占主角地位,主要产品为蝴蝶兰、大花蕙兰、凤梨、红掌、仙客来、杜鹃等主流花卉,微型月季、长寿花、蟹爪兰等小盆栽花卉销售看好.

In order to investigate the response of dry weight and morphological characteristics of flue-cured tobacco root system to drip nitrogen fertigation, 10 drip nitrogen fertigation treatments of different nitrogen ratios 0, 28, 42 days after transplanting were designed using the cultivar K326 in the frame conditions. Root dry weight, root-shoot ratio and root morphological indexes were assayed. The results showed that root dry weight, root-shoot ratio, root surface area at 15-25 cm in the vertical direction and 15-20 cm in the horizontal direction from the infusion point decreased with the increased rate of nitrogen topdressing. Root dry weight and root-shoot ratio of the T2 treatment (50% of the N fertilizer applied at transplanting plus 2 times of drip fertigation) were 27.08%, 3.61% and 13.79% higher than T1 (50% N applied at transplanting plus 1 drip fertigation), respectively. When 30% and 10% of the nitrogen fertilizer was applied at transplanting, two times of nitrogen topdressing caused a significant decrease in root dry weight, and an increase in root surface area at 20-25 cm in the vertical direction and 15-20 cm in the horizontal direction from the infusion point. In other words, to some extent, promoted the growth of root system which was deep in the soil and far from the plants. The 10 treatments had no significant effects on the average root diameter. Under the conditions of this experiment, appropriately increasing the ratio of nitrogen at the early growth stages can promote the growth of tobacco root system. Root growth can be further promoted by appropriately increasing the ratio of nitrogen topdressing, under the premise that the nitrogen at the root extending stage was adequate.

To study the effects of inorganic nitrogen (inorganic-N) combined with amino-acid nitrogen (glutamic acid, Glu) on the growth and relevant enzyme activities of tobacco seedlings, water culture experiment was conducted on cv. NC55 under asepsis condition to determine the root morphology, chlorophyll and carotene contents, and activities of key enzymes related to nitrogen metabolism of tobacco seedlings. Six treatments were set at different nitrogen forms and the same nitrogen concentration: NH4+-N (T1), NO3--N (T2), Glu-N (T3), NH4+-N:Glu-N=1:1 (T4), NO3--N:Glu-N=1:1 (T5) and NH4NO3-N:Glu-N=1:1 (T6). The results showed that the total length, surface area and total volume of roots and the length of first lateral root in T3 were the highest and the total root length in T6 was higher. The contents of chlorophyll a, chlorophyll b and carotene in tobacco leaves in T4 were the highest. The contents of leaf photosynthetic pigments in the treatments of inorganic-N combined with Glu were higher than those in N treatments alone. The leaf glutamine synthetase (GS) activity in T3 was the highest and the leaf GS activities in the treatments of inorganic-N combined with Glu were higher than those in N treatments alone. The root glutamic-pyruvic transaminase (GPT) activities in the treatments of inorganic-N combined with Glu were obviously higher than those in N treatments alone. The leaf glutamic-oxaloacetic transaminase (GOT) activity in T6 was the lowest, and the root GOT activities in the treatments of inorganic-N combined with Glu were higher than those in T2 and T3. Glu was favorable for root elongation and lateral roots formation. Inorganic-N combined with Glu could alleviate the adverse effect of inorganic-N on root growth and improve pigment synthesis in leaves. Applying Glu could increase leaf GS activity, and inorganic-N combined with Glu could enhance root GOT and GPT activities.

近年来,按照一二三产业融合发展的要求,江苏省休闲农业快速发展.本文对江苏省休闲农业产业发展现状进行总结,进一步提出江苏省休闲农业现存的问题与发展建议,期望通过坚持绿色发展理念,合理规划布局,加强宣传推介,挖掘文化深度等措施,加快推进江苏省休闲农业供给侧结构改革进程.

为探讨不同形态氮素对烟草根系生长和氮素利用的影响,以烤烟品种NC55为材料,在水培条件下,设置相同氮浓度不同铵硝配比的5个处理（T1 NH 4 + -N:NO 3 - -N=100:0;T2 NH 4 + -N:NO 3 - -N=70:30;T3 NH 4 + -N:NO 3 - -N=50:50;T4 NH 4 + -N:NO 3 - -N=30:70;T5 NH 4 + -N:NO 3 - -N=0:100）,研究了不同氮素形态营养下根系形态生理特征及各器官氮素积累分配的差异,结果表明:处理后25d,纯铵态氮处理的烟苗地上部干重和总干重,总根长、根系总表面积、总体积、可溶性糖含量及茎和叶的含氮量、氮积累量与氮分配率均最低;纯硝态氮处理的烟苗根系干重、平均直径与活力及根系含氮量与氮积累量最低。处理20d内,铵硝比50:50的处理根系干重、氮积累量和植株总干重最大。处理后25d,铵硝比70:30的处理根系和地上部干重,根系总体积、总表面积、活力与可溶性糖含量及根系含氮量与氮积累量最高;铵硝比30:70的处理叶片含氮量与氮积累量最高。在2 mmol/L的氮浓度下,单施铵态氮或硝态氮抑制了烟苗生长及对氮素的利用,混施铵态氮和硝态氮促进烟苗的生长发育及对氮素的利用,其中铵硝比70:30促进烟苗根系与地上部的协调生长,铵硝比30:70促进烟苗地上部对氮素的吸收利用。

In order to investigate the response of root growth, C and N accumulation of flue-cured tobacco seedlings to different nitrogen forms, hydroponic experiments were conducted by supplying equal amount of N in three different ratios of NH4+:NO3- (100:0, as 100-0AN; 50:50, as 50-50AN; 0:100, as 0-100AN) to seedlings of flue-cured tobacco cultivar NC55. Plant dry biomass, root morphology, C and N content, C and N accumulation were assayed during the cultivation. The results showed that shoot and total biomass showed 0-100AN>50-50AN>100-0AN at all treating times. On 7 and 14 d, root biomass, root total length, root total volume, root total surface area, C and N accumulation of root, stem, leaf and total nitrogen accumulation showed 0-100AN>50-50AN>100-0AN. On 21 d, the same parameters showed 50-50AN>0-100AN>100-0AN. Ammonium as sole nitrogen source inhibited flue-cured tobacco growth. Nitrate is beneficial to shoot growth and carbon accumulation, it however inhibits root growth as sole nitrogen source for prolonged time. Optimum nitrogen form for root development, C and N accumulation is the mixture of ammonium and nitrate.

Taking tobacco cultivar NC55 as material, the effects of combined application of soybean cake fertilizer and inorganic fertilizer on inorganic nitrogen supplication and related enzyme activity in tobacco plant -ing soil were studied .The results indicated that the soil inorganic nitrogen content reached the maximum at 50 th day after tobacco transplanted , and the treatment of 30%soybean cake and 70%inorganic fertilizer had higher content than the others .The soil sucrase , urease and nitrate reductase activity of the treatment of only inorganic fertilizer were always below than other treatments .Combined application of 70% soybean cake and 30%inorganic fertilizer had higher sucrase , urease and nitratase activity than the others in the tobacco grow-ing critical period .

Ammonium and nitrate,as the main inorganic nitrogen forms absorbed from the soil,had different effects on morphological and physiological processes in higher plants. This paper reviewed the mechanism of different nitrogen forms absorption and utilization in plants, how nitrogen form regulating nutrient uptake, root system development,photosynthesis physiology, yield and quality formation, and nitrogen transporter protein genes expression etc.. The paper also elaborated the mechanism of nitrogen forms regulating plant growth,and put forward problems needed to be clarified in studying nitrogen form.