This study aims to excavate the SNP loci and candidate genes significantly associated with the seed number per silique（SPS）in Brassica napus L. Having 300 B. napus inbreeding lines as experimental materials, we investigated the phenotypes of SPS under two locations(Jiangxi Agricultural University（JXAU）in Nanchang and Jiangxi Institute of Red Soil（JXIRS）in Jinxian in a year. Then we conducted the genome-wide association study via general linear model（GLM）and mixed linear model（MLM）combining 201 817 SNPs markers determined previously. And finally we predicted the functions of relevant candidate genes within the 100 kb region flanking trait significantly associated SNP loci. The results showed that the broad phenotypic variations of SPS in the two locations among the 300 300 B. napus samples existed, and two germplasm with more SNP were screened. Total 39 SNPs loci remarkably associated with SPS were excavated by general linear model（GLM）. Furthermore, 3 SNPs of SPS were detected severally using the mixed linear model（MLM）, and they all were detected using GLM. And 19 candidate orthologous genes to documented Arabidopsis the seed number per silique, like CIK, ERF022 and EDE1, were found near our eight SNPs loci. The results are conducive to analyzing the genetic basis of SPS of rapeseed and would lay a foundation for studying the regulation mechanism and guiding the genetic improvement of SPS.

利用江西省26个气象站点1991～2020年的日最低气温观测资料,探讨了江西省各地区茶叶春霜冻害发生天数的年际变化和高发时段,分析了江西省各地区重度、中度和轻度茶叶春霜冻害发生的频率,计算了江西省各地区茶叶冻害风险指数并进行了风险区划.结果表明:(1)近30年来,江西省年平均春霜冻害发生日数平均为3.71 d,茶叶春霜冻害天数以-0.847 d/10 a的倾向率显著下降(P<0.05);(2)近30年来,江西省的茶叶春霜冻害主要发生在3月上旬,占总发生天数的48％,3月中、下旬也有相当的比例发生茶春霜冻害,占总发生天数的30.06％～41.61％;(3)近30年来,江西省的茶叶春霜冻害发生频率相对较高,除赣南地区春霜冻害发生频率相对较低外(55.83％),其他地区茶叶春霜冻害发生频率均在75％以上,其中江西省各地区以轻度春霜冻害为主,赣中、赣西北和赣东北这3个地区的中度春霜冻害发生频率相对较高(≥27.92％),此外,赣西北的重度春霜冻害也有较高的发生频率(28.75％);(4)近30年来,江西省春霜冻害风险指数(I)平均为0.36,各地区表现为赣南(0.22)

为探究地表不同覆盖物对茶树低温冻害及茶园地温时空变化的影响,指导茶农有效开展冻害预防,采用稻草、白膜、防草布3种材料对茶园地表进行覆盖,同时以不覆盖为对照,比较极端低温下茶园土壤温度时空变化和茶树冻害的发生情况,分析地表最低温度、日较差、低温持续时间与茶树受冻率之间的相关性.结果表明,白膜、稻草、防草布覆盖均能提高土壤地表最低温度,比对照分别高2.9、2.6、0.9℃,减轻茶树受冻程度,覆白膜和稻草处理的茶树受冻率均显著低于对照和覆防草布处理.覆白膜具有增温作用,能提高不同深度土壤的最低温度和最高温度,使其较对照分别平均提高1.0～2.9℃和1.0～4.7℃,增温效果大于覆盖其他材料;覆稻草具有高温时降温和低温时升温的双向调控作用,增加了同一深度土壤温度的稳定性,日较差最小,降温效果最好;覆防草布降温不如覆稻草,增温不如覆白膜.地温时空变化主要体现在表层土壤,地下土壤与表层土壤相比温度变化趋于平缓;沿着土壤深度方向,土壤温度峰值出现的时间延后.茶树受冻率与地表平均最低温度、地表温度＜0℃最长持续时间呈显著相关,与地表温度＜4℃最长持续时间呈极显著相关,地表温度＜0℃不是茶树受冻的临界温度,当茶园地表温度0～4℃,持续时间大于7 d且日持续时间大于13.5 h,茶树仍可发生冻害.因此,从预防茶园低温冻害考虑,覆盖材料推荐使用白膜和稻草;从保持土壤温度的稳定性考虑,推荐使用稻草.

根据庐山云雾茶制作名优茶对鲜叶原料的要求,以一芽一、二叶及其同等嫩度的对夹叶为标准芽叶,研究三个采摘时期机采鲜叶的机械组成变化规律.结果表明,标准芽叶达70％～80％(采摘期二)时机采,可以获得较高比率的名优茶原料,为机采适期.本试验条件下,按采摘期二标准进行名优茶机采,春茶机采间隔期18～19d 为宜.嘉茗1 号茶树品种与迎霜相比更适合机械采摘.

为应对极端低温天气对江西茶区的困扰和威胁,探索科学有效的茶园冻害减灾避灾技术措施,本研究设置围挡措施,通过阻碍冷空气的平流运动对茶树叶片的直接接触,分析比较不同处理温度变化和冻害差异,探讨冻害影响因子之间的关联性、贡献率,并计算冻害发生阈值.结果表明:与对照相比,围布与围布+膜处理可以有效减少低温(≤0℃)发生天数、持续时间以及负积温,发生天数减少1～3 d,持续时间减少10.16％～17.11％,负积温下降5.72％～20.23％;可以缩小空气温度的波动范围,日较差降幅12.08％～18.64％;可以减轻茶树低温冻害,受冻率下降了2.11％～8.0％.相关性分析表明,茶树受冻率与平均日最低温度、极端日最低温度、平均日温度呈极显著负相关(P<0.01),与日低温持续时间、日低温积温呈极显著正相关(P<0.01),与平均日较差不相关(P>0.05).主成分分析得出,平均日最低温度、平均日温度、日低温持续时间为低温冻害主导因子,贡献率为89.69％.此外,通过曲线拟合计算出10％冻害发生率的平均日最低温度阈值为-0.77℃.综上所述,围挡措施能有效缓解茶园冻害,围布+膜是当前茶园冻害预防值得推广的技术.

为探究越冬期不同的覆盖材料对茶园土壤温度及茶叶产量、品质的影响,寻求效果佳的防冻材料,研究采用稻草、白膜、黑膜、稻谷壳和防草布等5种材料在茶园行间进行地表覆盖,比较不同材料覆盖后对土壤温度和茶叶产量、品质,以及春茶萌发时间的影响.结果表明,相较于未进行覆盖的对照,5种覆盖处理均能提高土壤温度,平均增温1.5～2.9℃,且覆盖后可使茶叶产量提高4.3％～13.6％,春茶萌发时间提早2～4 d,其中增温效果稻草和稻谷壳优于其他材料.使用稻草和稻谷壳覆盖后,茶叶水浸出物、咖啡碱、茶多酚、氨基酸含量均有所提高.综合比较来看,稻草和稻谷壳的增温效果较黑膜、白膜和防草布更好,而且能提高茶叶产量与品质,更适合作为茶园越冬期防冻的覆盖材料.

通过室内培养试验,研究了粉葛废弃物(质量比:1％、2％、3％、4％、5％)对镉(Cd)污染农田土壤pH、有机质及Cd赋存形态的影响.结果表明,经49 d修复后,与对照相比,添加粉葛废弃物处理的土壤pH升高了0.34～1.19,有机质增加了2.23～10.00 mg/kg,Cd弱酸提取态降低了6.61％～26.64％,Cd残渣态增加了1.26％～59.44％,而Cd可还原态和Cd可氧化态影响较小.同时,土壤pH、有机质与Cd弱酸提取态呈显著负相关(p<0.01),与Cd残渣态呈显著正相关(p<0.05).总体上,培养时间对Cd弱酸提取态并无明显影响;钝化效果随添加比例的增加逐渐增强;综合降镉效果和添加量,以3％处理最优.粉葛废弃物对Cd污染农田土壤具有较好的钝化效果,这为Cd污染农田土壤修复和农业废弃物的循环利用提供了参考.

为促进区域茶园科学合理施肥,以当地茶园推荐的化肥施用量为对照(CK),设置了6个梯度有机肥施用量作为处理,即:3000(FQ1),4500(FQ2),6000(FQ3),7500(FQ4),9000(FQ5),12000 kg/hm2(FQ6),分析了有机肥施用量对茶叶产量和品质、土壤养分及氮素利用的影响.结果表明:不同处理对茶叶产量及产量性状存在极显著影响(P<0.01);与CK相比,养分投入量相当(或更少)条件下施用有机肥造成了茶园产量及产量性状不同程度地下降(降幅为4.32％ ～32.28％),进一步增加有机肥施用量才可获得较好的产量及产量性状.与CK相比,有机肥施用量≥4500 kg/hm2时提高了茶叶水浸出物含量,其中FQ6处理茶叶水浸出物含量得到显著提高(P<0.05);施用有机肥对茶叶茶多酚和氨基酸含量的影响相对较小,仅2019年FQ5和FQ6处理显著提高了茶叶氨基酸含量及2020年FQ1处理显著降低了茶叶茶多酚含量(P<0.05);有机肥施用量对茶叶咖啡碱及酚氨比不存在显著影响(P>0.05),但一定程度提高了茶叶咖啡碱含量并降低了茶叶的酚氨比.与CK相比,不同有机肥施用量均可缓解茶园土壤酸化状况并显著提高茶园土壤碱解氮含量(P<0.05);除FQ1处理,施用有机肥处理显著提高了茶园土壤有机质和速效钾含量(P<0.05);FQ1显著降低了茶园土壤有效磷含量(P<0.05),而FQ5(2019年)和FQ6处理显著提高了土壤有效磷含量(P<0.05).氮素盈余量和氮肥偏生产力随着氮肥施用量的增加分别表现出极显著增加和下降趋势(P<0.01),其中:CK与养分投入量相当条件下施用有机肥(FQ3处理)的氮素盈余量和氮肥偏生产力差异不显著(P>0.05);氮素盈余量、氮肥偏生产力与氮肥施用量的关系分别呈线性(y=0.786x-115.04,P<0.01)和幂函数关系(y=635.28x-0.605,P<0.01),即随着肥料氮投入的增加,氮素盈余量和氮肥偏生产力分别呈增加和下降趋势.基于2019,2020年的茶叶产量反应,应用线性加平台模型拟合每年有机肥最佳施用量为8739.55～9169.95 kg/hm2,但造成氮素盈余量过大和氮肥偏生产力较低,并增加了环境污染的风险.综上,茶园施用有机肥虽然降低了产量,但提高了茶叶品质,改善了茶园土壤养分状况;同时,从氮素利用角度考虑,茶园施用有机肥时不应过分追求茶叶产量,可适当降低有机肥施用量以控制氮的投入.

为了明确油菜秸秆还田配施石灰对红壤稻田酸化改良和培肥的效果,2018年早稻季在典型的酸性红壤双季稻田(江西进贤)开展石灰和油菜秸秆还田双因素小区试验,分析油菜秸秆还田配施石灰对早稻产量形成、土壤pH及速效养分的影响.结果表明,施用石灰和油菜秸秆还田均显著促进了早稻高产的形成,且二者具有显著的互作效应.在秸秆还田条件下,配施石灰使早稻增产11.4％;而在秸秆不还田条件下,增幅仅为6.3％.油菜秸秆还田并配施石灰协同促进了早稻分蘖成穗、地上部养分(氮、磷、钾)吸收及干物质积累,从而扩大了总颖花量,提高了有效穗数和每穗粒数,同时,能够快速改良土壤酸化并增加耕层速效养分.因此,油菜秸秆还田配施石灰可改良酸性红壤稻田土壤,实现早稻增产.

为探讨马铃薯-中稻-再生稻不同覆盖方式下马铃薯的生长发育特性,选用裸地(M1)、稻草包芯覆盖(M2)、黑色地膜覆盖(M3)、稻草包芯+黑色地膜覆盖(M4)4种覆盖方式,以4个马铃薯品种为材料,采用2因素裂区设计对不同覆盖方式下马铃薯出苗时间及出苗率、大中薯率、产量和经济效益进行研究.结果表明,在所有处理中,M4处理的出苗率最高,分别比M3、M2和M1处理提高了1.62％、2.65％、7.71％.马铃薯的株高、主茎数、大中薯率和产量均表现出M4>M3>M2>M1.而不同品种的产量则以兴佳2号最高,分别比华薯2号、中薯5号、费乌瑞它提高了90.86％、98.70％、103.17％.同时,M4处理下兴佳2号的产量分别比M3、M2和M1处理增加了17.32％、30.70％和43.17％,产投比则分别提高了13.14％、22.22％、41.43％.方差分析表明,品种对产量的影响最大,覆盖方式对出苗率影响最大.因此,稻草包芯+黑色地膜覆盖技术可改善马铃薯大中薯率,能显著增产增收,是江西三熟制地区的高效栽培模式.

为探索茶园杂草生长的时空规律,给茶园杂草防控提供数据支撑和理论依据,笔者于2019年春、夏、秋季调查了江西省婺源县不同地区茶园杂草的种类、数量和生物量等,并分析了季节、海拔和茶树高度对杂草种类组成与生物多样性的影响.结果表明,婺源茶园有65种杂草,分属33科61属,春季有20科27属31种杂草,夏季有25科37属39种杂草,秋季有20科33属34种杂草,其优势种为菊科和禾本科,以马唐(Digitaria sanguinalis)、酸模叶蓼(Polygonum lapathifolium)、蕨(Pteridium aquilinum)、看麦娘(Alopecurus aequalis)、酢浆草(Oxalis corniculata)、蓬蘽(Rubus hirsutus)、狗尾草(Setaria viridis)等出现的频率较高.茶园杂草多度表现为春季>夏季>秋季,丰富度、香农-维纳多样性指数和辛普森多样性指数表现为夏季>春季>秋季,生物量和Pielou均匀度指数表现为夏季>秋季>春季;茶园杂草多度随海拔上升而减少,丰富度、香农-维纳多样性指数、辛普森多样性指数和Pielou均匀度指数均随茶园海拔上升而增加,生物量以中海拔地区最高;杂草多度和生物量随茶树高度增加而降低.总体而言,婺源茶园杂草种类丰富,夏季和高海拔地区的杂草多样性较高,幼龄茶园杂草多样性较低.

探究白云石粉不同施用量对茶园土壤酸化、茶叶产量及品质的影响效果,以期寻找到土壤降酸、茶叶提质的最佳白云石粉施用量.采用田间试验,设置0 kg/hm2(CK)、375 kg/hm2、750 kg/hm2、1500 kg/hm2、2250 kg/hm2等5个不同处理.结果表明,白云石粉施用量大于1500 kg/hm2时, 0~20 cm、20~40 cm土层土壤pH值显著增加,交换性酸显著降低;施用量为1500 kg/hm2,茶叶水浸出物、咖啡碱、茶多酚、氨基酸、百芽重、产量、芽密度均显著高于其他处理,酚氨比显著低于其他处理.白云石粉施用量为1500 kg/hm2,能够有效改善茶园土壤酸化,提升茶叶品质,增加茶叶产量.

为了有效控制井冈山茶园杂草,2018—2019年调查了江西省井冈山主要茶叶产区高山、低丘陵茶园的杂草密度与种类及生活型,分析杂草危害特点.杂草种类调查结果表明:井冈山市茶园有杂草112种,共涉及45科,杂草区系丰富,其中以菊科、禾本科、豆科、旋花科占比高,分别为14.29％、9.82％、5.36％和5.35％;杂草生活型及危害特点结果表明:低丘陵茶园杂草以禾本科等一年生杂草为主;高山茶园以多年生杂草为主,防治难度更大.通过对井冈山茶园杂草多样性分析,为茶园绿色防草技术提供依据.

为明确油稻稻三熟制秸秆还田条件下双季水稻适宜的氮肥运筹方式,2018年在长江中游三熟制区(江西进贤)开展5个处理(秸秆不还田+氮肥3次施用、秸秆还田+氮肥3次施用、秸秆不还田+氮肥2次施用、秸秆还田+氮肥2次施用、秸秆还田+高量氮肥3次施用)的田间试验,探究该模式下氮肥运筹对双季稻产量与氮素吸收利用的影响.结果表明,在油稻稻三熟制下,秸秆还田和氮肥运筹对水稻产量的影响在早稻季和晚稻季均存在显著的互作效应,而水稻基肥中增施20％氮肥对产量的影响不明显,氮肥2次施用(后氮前移)即可实现水稻高产和稳产.秸秆还田并配合氮肥2次施用(后氮前移)可以满足水稻生育期氮素需求,从而保证水稻正常生长,氮素吸收量能够达到甚至优于3次施氮处理水平,并明显提高氮肥利用率,增加氮肥用量则不利于氮肥偏生产力的提高.

To investigate soil fertility status and characteristics of typical tea plantations, we selec-ted 372 typical tea plantations of 21 areas across Jiangxi Province and analyzed the soil nutrient, spatial data, and their correlations with topography, soil type, elevation and plantation age. The results showed that soil pH, organic matter, alkaline nitrogen, available phosphorus, available potassium, total nitrogen, total phosphorus and total potassium of tea plantation in Jiangxi reached 53.9%, 60.1%, 56.1%, 22.9%, 38.5%, 43.7%, 11.1% and 95.5% of indices of high fertility, high efficiency and high yield tea plantation, respectively, with the available phosphorus showing a strong variation. Soil available copper, zinc, iron, manganese and boron reached 76.3%, 74.2%, 96.8%, 73.1% and 0.0% of the first-class standards for soil trace elements, respectively. Tea plantations with highest soil fertility located in central Jiangxi, followed by northeastern and northwestern Jiangxi, and lowest in southern Jiangxi. Soil pH was significantly positively correlated with organic matter, alkaline nitrogen, available phosphorus, available potassium, total nitrogen and total phosphorus but not for total potassium. For different topography, soil fertility was highest in the flat land, followed by the high mountains, and lowest in the mountains and hills. Across different soil types, soil fertility was higher in paddy soil, sandy soil and mountain yellow brown soil, followed by yellow soil, red-yellow soil and purple soil, and lowest in red soil. Soil pH, organic matter and total potassium increased while available phosphorus decreased with altitude. The organic matter, alkaline nitrogen, available phosphorus, total nitrogen and total phosphorus increased, but soil pH decreased with time. In summary, soil fertility of tea plantations in Jiangxi Province was generally good, with high organic matter, total potassium, available copper, zinc, iron and manganese. However, soil was acidic, available phosphorus and total phosphorus content was low, available boron was seriously limited. We suggest increase soil pH and potassium supply in central Jiangxi, increase potassium and nitrogen fertilizer supply in northeastern Jiangxi, increase organic matter and phosphorus fertilizer supply in northwestern Jiangxi, and increase nitrogen, phosphorus and potassium supply combined with organic fertilizers in southern Jiangxi. High mountain tea plantations should enhance available phosphorus and potassium supply. Mountain tea plantations should enhance nitrogen and phosphate supply. Tea plantations with red and yellow soil should increase pH and total potassium supply. Tea plantations with red soil should apply nitrogen, phosphorus and potassium fertilizers combined with organic fertilizers. Tea plantations with yellow soil and mountain yellow brown soil required additional phosphorus supply, and tea plantations with purple soil should increase soil organic matter supply. Tea plantations need to increase dolomite powder, physiological alkaline fertilizers and organic fertilizers to prevent soil acidification.

为明确油-稻-稻三熟制油菜秸秆还田条件下早稻的适宜施氮量,2017-2018年以超级常规早稻中嘉早17为材料,设置0、75、120、165、210kg/hm2等5个施氮量,探究油菜秸秆还田条件下施氮量对早稻产量形成及氮素吸收利用的影响.结果 表明:在油菜秸秆还田条件下,适宜施氮量有利于早稻分蘖成穗,灌浆期维持较高的叶面积指数、光合势和干物质积累量,同步增加单位面积有效穗数和保持较多的每穗粒数,从而扩大总库容量.在施氮量为165kg/hm2时早稻即可达到较高产量,同时维持较高的氮肥吸收利用率.采用线性加平台模型拟舍得出最佳施氮量,2017和2018两年分别为155.91、160.37kg/hm2,产量潜力分别达8 241.17和8 387.32kg/hm2.

为充分利用植物用低温等离子体的物理性能及其生理诱活、诱抗效果,开辟茶园绿色、安全、高产技术新途径,本研究以喷清水为对照,设置了喷施300倍、600倍、900倍、1200倍4种处理,比较不同处理对茶叶生理生化的影响效果.结果表明:喷施植物用低温等离子制剂可提高茶树叶片叶绿素10.1％～21.3％,提高茶青产量8.74％～41.73％,可使鲜叶茶多酚含量降低3.79％～6.28％、氨基酸含量提高0.17％～0.46％.研究还得出喷施600倍为茶园应用最佳剂量.

[Objective]A reasonable depth of cultivation which would not only effectively prevent the deterioration of soil structure but also could fully create a well-developed environment such as water,fertilizer and air for tea plants was studied to provide technical ways for guiding tea farmers in scientific farming.[Method]In this study,fild experiment was conducted. No tillage was as control(CK). Three tillage depths including,10 cm tillage,20 cm tillage and 30 cm till-age were set to study the effects of various tillage depths on soil bulk density,water content,porosity,three-phase ratio and nutrient.[Result]Compared to CK,soil bulk density of 0-30 cm layer decreased to various extents after tillage,and that in 30 cm tillage treatment significantly reduced(P<0.05,the same below). Tillage significantly increased soil water content,and 20 cm tillage had the best effects on 0-10 and 10-20 cm soil layer,30 cm tillage had the optimal effects on 20-30 cm soil layer. In addition,tillage also increased non-capillary porosity,but reduced capillary porosity. Overall the total porosity still increased. Tillage had significant effects on soil porosity at the depth of 0-10 cm. The soil porosity was significantly affected by 20 cm tillage at the depth of 10-20 cm,while 30 cm tillage had significant effects on the noncapi-llary and total porosity at the depth of 20-30 cm. After tillage,the gas phase and liquid phase ratios at the depth of 0-10 cm increased significantly,while the solid phase ratio decreased significantly,and 20 cm tillage had the optimal effects. While 30 cm-tillage had the best coordination effects on three-phase ratio at the depth of 20-30 cm. After tillage,the con-tent of organic matter at the soil depth of 0-10 cm decreased,while the content of organic matter at 20-30 cm increased significantly under 20 cm and 30 cm tillage. The content of readily available nutrient at the soil depth of 0-30 cm increased to different degrees after tillage. An analysis of principal components showed that the total porosity and solid phase ratio were the key factors that affected the soil physical properties of the tea plantation,while the available phosphorus was the key factor in nutrient fertility index.[Conclusion]To sum up,different tillage depths can reduce soil bulk density,in-crease soil water content,improve soil porosity and coordinate three-phase ratio of soil,and 20 cm tillage has the best ef-fects on comprehensive improvement of tea plantation soil.

目前测定土壤有机质含量的常用方法为油浴法,但油浴法操作繁琐,易污染空气,且试管不易清洗.针对存在的这些问题,把油浴法消煮方式改为用三角瓶直接在180℃烘箱加热15 min,通过对土壤标准物质进行检测分析以及和传统油浴法进行比较,结果表明,使用该方法测定的土壤标准样品的有机质含量均在标准值允许范围内,相对误差均小于1.5％,相对偏差均小于2.0％,在0.01水平下与油浴法差异不显著.该方法准确度较高,重现性好,操作更加安全迅速,适合大批量样品的分析,因此可作为土壤有机质含量测定的一种参考方法.

为了探究生物黑炭对茶园酸化土壤的改良效果,寻找对土壤改良效果好、能提升茶叶品质、增加茶叶产量的最佳生物黑炭施用量,指导茶农科学改良酸化土壤,实现茶叶优质高产.采用田间试验,设置0t/hm2(CK)、15t/hm2、30t/hm2、60t/hm2、90t/hm25个不同处理,研究生物黑炭施用量对酸化茶园土壤交换性酸、 茶叶品质和产量的影响.结果表明,与CK相比,施用不同用量的生物黑炭处理:0～20 cm土层土壤pH值提高0.25～1.62个单位,交换性酸降低11.5～4.83 cmol/kg;20～40cm土层土壤pH值提高0.04～0.38个单位,交换性酸降低0.01～3.1 cmol/kg.当生物黑炭施用量大于等于15 t/hm2时,各处理氨基酸均与不施用生物黑炭(CK)差异性显著(P<0.05);当生物黑炭施用量大于等于30 t/hm2时,酚氨比较不施用生物黑炭(CK)显著降低(P<0.05).百芽重增加2.05％～16.77％,发芽密度增加4.33％～9.45％,但与CK相比,差异均不显著(P>0.05).产量与对照相比,增幅-5.29％～14.45％.综上试验结果认为,施用30 t/hm2的生物黑炭能够有效改善茶园土壤酸化情况,提升茶叶品质,增加茶叶产量.