干旱胁迫对不同烤烟品种根系生长和生理特性的影响

以抗旱型烤烟品种‘农大202'及一般型烤烟品种‘NC89'和‘K326'为材料,采用盆栽试验研究了干旱胁迫对根系生长和生理特性的影响,以明确各烟草品种的抗旱能力及其与根系生长和生理特性的关系.结果显示:严重干旱胁迫之后各烤烟品种根系鲜重、干重上升,而根系活力、根系吸收面积以及根系SOD和POD活性等根系生理指标则呈下降趋势.在干旱胁迫条件下,‘农大202'的根系总吸收面积、活跃吸收面积、根系活力、SOD活性和POD活性均显著高于两对照品种‘NC89'和‘K326',但其根系鲜重和干重等生物量并不具有太大的优势.研究表明,烟草的根系生长和生理特性对环境水分条件的响应存在明显的基因型差异;在干旱胁迫条件下, ‘农大202'根系能保持较高总吸收面积、活跃吸收面积、根系活力和保护酶活性,是其具有较强抗旱性的生理基础.     

不同品种春小麦根系对低钾胁迫的生物学响应

采用水培法,以3个春小麦品种(加春1号、2号、4号)为试验材料,研究了低钾胁迫下不同品种春小麦根系的形态学与生理学特征。结果表明:(1)与对照相比,低钾胁迫下小麦的根重、根数、总根长、总吸收面积、根活力、根系SOD及POD活性、根系活性吸收面积均明显降低,但根冠比有所增加,不同春小麦品种间的变化趋势相似,但变化幅度存在明显差异。(2)供试品种小麦根系的形态与生理学特征在同一供钾水平下和不同供钾水平间均存在着明显的差异,表明这两种性状的差异是由基因型和环境因素共同决定的,因此,根系形态学和生理学特征可以作为筛选高效吸收钾小麦品种的参考指标。(3)供试的3个春小麦品种中‘加春4号’对低钾环境的适应性最强。     

烟草磷效率的基因型差异及其与根系形态构型的关系

以17个具有代表性的主要烟草基因型为材料,通过盆栽试验和培养基栽培试验,研究烟草磷效率的基因型差异及其与根系形态构型的关系,为磷高效烟草品种选育提供理论依据.结果表明,施磷肥能够显著增加各供试烟草基因型的生物量及氮、磷和钾的累积量;供试烟草的磷效率和氮、钾累积量存在显著基因型差异,土壤盆栽试验中,低磷条件下的'云烟85'生物量和磷累积量分别是'NC82'的4.06倍和3.34倍,氮和钾累积量分别是'K358'的4.06倍和3.75倍;供试烟草可划分为磷低效低产型、磷低效高产型、磷高效高产型、磷高效低产型等4种类型,其中的'云烟85'、'K326'、'云烟2号'、'RG11'和'红花大金元'属于磷高效高产型,是现代磷高效高产品种选育的理想材料.供试烟草基因型的根系形态构型与其磷效率显著相关,与磷低效低产型烟草'G28'和'许金1号'相比,磷高效高产型烟草'云烟85'和'K326'在高低磷条件下根系均较发达,总根长和根表面积均较大;磷有效性对烟草根构型具有调节作用,在缺磷条件下,磷高效基因型具有浅根根构型,而磷低效基因型具有深根根构型.     

不同基因型烤烟钾吸收特性差异及吸收机理

以富钾植物烟草为研究对象,烤烟基因型ND202、NC628、G28、NC628×ND202为材料,分析了不同基因型间根系特性及其对矿物钾活化能力的影响差异.结果表明： 根系对矿物钾活化总量越高,烤烟的钾积累量越高.ND202根系发达,富钾能力强,但受环境中钾含量影响较大;NC628根系矿钾活化能力较强,能够显著提高根际土壤钾有效性,但富钾能力较弱;杂交种NC628×ND202较母本具有较高的矿钾活化能力及耐低钾能力,较父本有较高的干物质积累量及富钾能力.因此,利用杂交培育高钾品种是有效的,选育高钾品种时,亲本不仅应具有较高的配合力,更应优先考虑其能否提高根际土壤钾的有效性.     

不同烤烟品种抗旱生理特征比较研究

以4个抗旱性不同的烤烟品种(系)为材料,采用盆栽试验测定了它们在干旱胁迫条件下的生物量以及叶片相对含水量、保水力、净光合速率、脱落酸含量等生理指标,并用隶属函数法对它们的抗旱性进行综合评价,以探讨烤烟的抗旱生理机制.结果表明:在干旱胁迫条件下,各品种烟株的鲜、干重积累量、叶片相对含水量及净光合速率均下降,但'豫烟6号'和'农大202'降幅相对较小;各品种烟株的丙二醛和脱落酸含量在干旱胁迫下均显著增加,且脱落酸含量以'豫烟6号'的增加量最大,'NC89'最小,丙二醛含量以'NC89'增加量最大,'农大202'和'豫烟6号'相对较小;'豫烟6号'在干旱胁迫下的叶片保水能力极限著差高于'K326'、'NC89'; 隶属函数法综合分析结果显示,'豫烟6号'的抗旱性最强,'农大202'次之,'NC89'最差.研究发现,各烟草品种的植株形态和生理指标在干旱条件下存在明显的差异,抗旱性强的品种表现出较高的叶片保水力、净光合速率、生物量和脱落酸含量,以及较低的丙二醛含量,且除脱落酸含量外大多指标的升降幅度较小.     

聚乙二醇模拟干旱对耐低钾水稻幼苗的根系生长及某些生理特性的影响

以早籼品种‘瑰宝八号’及其变异后代耐低钾的水稻为材料,用20%PEG6000模拟干旱,测定幼苗根系形态和部分生理特性的指标并对其抗旱能力进行比较的结果表明:耐低钾水稻幼苗的超氧化物歧化酶活性、根系活力和活跃吸收面积相对较高,而丙二醛含量相对较低,其根重和根体积也高,比其亲本‘瑰宝八号’有更高的抗旱能力.     

低磷胁迫下磷高效基因型大麦的根系形态特征

在根袋土培盆栽条件下,以磷高效基因型DH110+、DH147和低效基因型DH49大麦为试验材料,利用根系分析系统分析不同施磷(P₂O₅)水平(极低磷25 mg·kg^-1、低磷50 mg·kg^-1和正常磷75 mg·kg^-1)下,磷高效基因型大麦的根系形态特征及其与植株磷素吸收的关系.结果表明： 低磷胁迫显著降低大麦生物量和磷吸收量,其中磷高效基因型的生物量和磷吸收量在各施磷水平下分别为低效基因型的1.24～1.70和1.18～1.83倍;大麦的总根长、总根表面积、平均根系直径、不定根长及其根表面积、侧根长及其根表面积均随施磷水平的降低而显著降低,其中磷高效基因型大麦在各施磷水平下的总根长、总根表面积、比根长、侧根长及根表面积分别为低效基因型的1.46～2.06、1.12～1.51、1.35～1.72、1.69～2.42和1.40～1.78倍,而平均根系直径为低效基因型的70.6%～90.2%;主成分分析表明,平均根系直径、比根表面积和比根长受基因型差异的影响较为明显,是区分两类磷效率基因型大麦根系形态差异的主要指标;偏最小二乘回归分析表明,各施磷水平下,总根长、总根表面积对大麦植株磷素吸收贡献均较大,随施磷水平降低,不定根长、不定根表面积对大麦植株磷素吸收的贡献明显降低,而平均根系直径、比根长、侧根长及其根表面积的贡献明显增加.磷高效基因型大麦可通过维持侧根的生长、根细度和比根长的增加来适应低磷胁迫.     

不同基因型春蚕豆对磷胁迫的适应性反应

利用不同作物或品种吸收利用土壤磷能力的差异提高磷素营养效率,是解决磷资源短缺的重要生物学途径.选择西北地区重要经济作物春蚕豆作为研究对象,选用3个不同春蚕豆品种(系),采用严重缺磷的碱性灌淤土,利用盆栽法研究了在不同供磷水平下不同基因型蚕豆的根系形态特征、酸性磷酸酶活性(APase)及产量的表现, 探讨不同基因型蚕豆对低磷胁迫的适应性反应.结果表明在整个生长过程中根长、根半径、根比表面积和根冠比变动最明显的是临蚕5号,分别为36.40%,65.10%、65.27%和13. 46%;缺磷条件下,蚕豆主要通过减小根半径,增加根长、根表面积,提高根冠比及体内酸性磷酸酶活性来实现对低磷胁迫的适应;不同基因型对低磷胁迫的适应能力不同;缺磷胁迫明显诱导各基因型蚕豆体内酸性磷酸酶活性的上升,临蚕5号增加最快为24.9%,8409为7. 79%,8354为7.29%;同一基因型的不同器官中酸性磷酸酶活性大小表现为根系>茎部>叶片 .根系酸性磷酸酶和根系形态参数可分别作为蚕豆耐低磷品种筛选的选择指标;缺磷导致作物减产,并且不同的基因型作物减产的幅度不同,临蚕5号缺磷比施磷减产30.98%,而8354 的产量在两个磷水平下变化不明显,说明临蚕5号对磷素的反应最强烈,为磷低效基因型,而 8354反应比较迟钝,为磷高效基因型.     

不同氮效率水稻品种根系生理生态指标的差异

以氮素利用效率差异大的两个水稻品种(氮高效品种南光和氮低效品种Elio)作为试验材料,设计高低两个供氮水平,在温室砂培条件下研究了不同氮效率水稻高效吸收利用氮素的根系生物学特性及生理机制.结果表明,在两个供氮水平下,氮高效水稻南光的产量均显著大于氮低效水稻,增幅在50%以上.随着供氮水平的提高,两个水稻品种植株的总吸氮量和干物质量随之增加,氮高效水稻南光的生育后期吸氮量和地上部及根系的生物量显著高于氮低效水稻Elio;氮高效水稻品种南光根系形态参数对氮素营养的响应度高于氮低效品种Elio,高氮处理下,南光较低氮处理分别增加127%(总根长)和114%(根系表面积),而Elio仅增加92%(总根长)和82%(根系表面积),而且Elio在齐穗期后根系形态参数水平下降显著;南光的根系伤流强度在拔节期较氮低效水稻Elio高出11%(1mmol L-1)和32%(5mmol L-1),灌浆期南光较Elio高出12%(1mmol L-1)和12%(5mmol L-1),差异均显著.由本试验结果可推断根系形态及根系活力的差异是造成水稻氮效率差异的重要原因之一.     

不同烤烟基因型钾离子通道特性研究

通过对4个不同钾营养效率的烤烟品种的根皮层细胞质膜内向跨膜钾电流进行全细胞记录,研究钾营养效率不同的烤烟基因型的钾离子通道的特性。结果表明,NC89的电流密度(pA/pF)最高,约为-80;其次是农大202及净叶黄,其电流密度分别为-60及-50;NC2326的电流密度在四个基因型中最小,大约-40。结果表明,烤烟根皮层细胞质膜跨膜内向钾电流的大小,与基因型对K+亲和力及吸收能力的大小,以及烤烟基因型钾营养效率高低有着密切的关系,可以作为一个比较可靠的参考鉴定指标,指导K+营养高效的基因型的筛选与鉴定。     

超绿水稻品种（系）‘沈农19-6’根系的生长和生理特性初探

采用盆栽方法,研究不同生育时期超绿水稻品种（系）‘沈农19-6’根系的生长和生理特性。结果表明,生育后期品种（系）‘沈农19-6’的最大根长、根体积、根干重和根冠比显著或极显著大于‘沈农07-015’和‘丰锦’;根系氧化能力（α-萘胺氧化量）和根系还原能力均高于‘沈农07-015’和‘丰锦’。上述指标在整个生育期内的变化趋势与‘沈农07-015’和‘丰锦’基本上一致,但在生育后期其根系衰老速度缓慢,根系活力高。     

玉米氮素吸收的基因型差异及其与根系形态的相关性

采用溶液培养的方法,选用在田间、土培试验中对氮反应有典型差异的玉米自交系：478、H21、Wu312、Zong31、Baici,在4个供N水平（0.04、0.4、2.4mmol/L）下,研究了玉米苗期氮素吸收、分配的基因差异以及与根系形态之间的相关关系,结果表明：在一定的NO3^-浓度范围内（0.04-2mmol/L）,根系生物量随N水平的提高而增加,而高N不同程度地降低了5个自交系根系干重。低N下（0.04mmol/L）,与其它自交系相比,N高效基因型478具有较大的根系生物量,其根系干重分别为H21、Wu312、Zong31、Baici的1.1、1.74、1.6、1.18倍,并往根系分配了较大比例的N素,根系N累积占总N量的百分率比Wu312、Zong31分别高18.34％、17.08％,而N低效基因型Wu312、Zong31则往地上部分配了较大比例的氮素。随N水平的增加,显著促进了地上部的生长,并在地上部分配了较大比例的N素。当N水平增至4mmol/L时,地上部N素分配的基因型差异减小。低N下,5个自交系根系干重、总根长、根轴总长与总吸N量显著线性相关,而高N下不表现相关关系,说明在N素胁迫的条件下,根系形态对N吸收效率起重要作用。     

Effects of varied soil nitrogen supply on Norway spruce (Picea abies [L.] Karst.)

During a seven-month period the effect of different nitrogen (N) availability in soil on growth and nutrient uptake was studied in three-year-old Norway spruce (Picea abies [L.] Karst.) trees. The plants were grown in pots on N-poor forest soil supplied with various amounts and forms (inorganic and organic) of N. Increasing supply of inorganic N (as NH₄NO₃) increased the formation of new shoots and shoot dry weight. The root/shoot dry weight ratio of new growth was drastically decreased from 1.6 in plants without N supply to 0.5 in plants supplied with high levels of NH₄NO₃. This decrease in root/shoot dry weight ratio was associated with distinct changes in root morphology in favour of shorter and thicker roots. The addition of keratin as organic N source did neither affect growth nor root morphology of the trees. The amount of N taken up by plants was closely related to the supply of inorganic N, and trees supplied with highest levels of NH₄NO₃ also had the highest N contents in the dry matter of needles and roots. In contrast, N contents in needles of trees grown without additional N, or with keratin supply, were in the deficiency range. Supply of NH₄NO₃ decreased the contents of phosphate (P) and potassium (K) and therefore markedly increased N/P and N/K ratios in the needles. On the other hand, the contents of calcium (Ca), magnesium (Mg), and manganese (Mn) in the needles were increased in the plants supplied with inorganic N, suggesting high soil availability and promotion of uptake of these divalent cations by high nitrate uptake. The observed effects on root/shoot dry weight ratio, root morphology, and mineral nutrient composition of the needles indicated that high inorganic N supply may increase above-ground productivity but at the same time decrease the tolerance of trees against soil-borne (e.g. deficiency of other mineral nutrients) stress factors. Deceased 21 September 1996 Deceased 21 September 1996     

Localized supply of phosphorus induces root morphological and architectural changes of rice in split and stratified soil cultures

A localized supply of phosphorus may affect root morphology and architecture, and thereby affect phosphorus uptake by rice plants. In the present study, we attempted to test this hypothesis using two rice cultivars representing upland and lowland ecotypes grown in specially designed split and stratified soil cultures with a low-phosphorus red soil. Our data indicate that a localized supply of phosphorus increased both total root length and root fineness, particularly in the high-phosphorus zone. In split culture, plants roots tended to preferentially grow on the high-phosphorus zone, with about 70–75% of the total root length allocated to the high-phosphorus compartment. The total root length on the high-phosphorus side in the split-phosphorus treatment was significantly longer than that in the homogenously high-phosphorus treatment, implying that a phosphorus-deficiency signal from the low-phosphorus side may stimulate the growth of the roots located in the high-phosphorus zone. In stratified soil culture, changes in root morphology and architecture were also observed as indicated by increased total root length, root fineness and relative root allocation in the high-phosphorus layers, again suggesting altered root morphology and preferential root proliferation in the high-phosphorus regions. The induced changes in root morphology and architecture by localized phosphorus supply may have both physiological significance and practical implications in that plants can meet the demand for phosphorus with parts of the roots reaching the high-phosphorus zone, hence localized fertilization methods such as side dressing or banded application of phosphorus fertilizers may both minimize phosphorus fixation by the soil and increase phosphorus uptake efficiency from the fertilizers.     

不同供水条件下水稻幼苗根系形成的遗传分析

利用分子标记图谱对溶液培养与旱作培养（纸培养）下的水稻（Oryza sativa L.)幼苗的种子根与最长不定根长,不定根数,总根干重,根冠比等性状进行了基因定位与遗传分析。4种参数共检测到6个数量性状位点（quantitative trait loci,QTLs)与22对上位性互作位点,其中溶液培养中的最长不定根长,总根干重和旱作培养中的总根干重检测到的QTLs位点对总变异的贡献率分别为20％,23％和13％左右;旱作培养中的最长不定根长,不定根数,根冠比和溶液培养中的根冠比仅检测到上位性位点,对表型变异的贡献率在12％－61％之间,溶液培养与旱作条件下没有一个或一对检测到的QTL或互作位点完全相同,提示溶液培养和旱作条件下影响幼苗根系生长的遗传机制差异,上位性作用对旱作培养条件下的根生长具重要影响。     

Effects of localized nitrogen supply treatments on growth and root parameters in Pinus massoniana families under phosphorus deficiency

Aims A heterogeneous spatially distribution of nutrients in natural soil may affect plant growth. The objective of this study was to determine the effects of localized nitrogen (N) supply treatments on growth traits and root parameters among different families in Pinus massoniana.Methods Five families of P. massoniana seedlings from full-sib progenies were used as test materials (1, 25, 49, 52, and 57). This study included two conditions, (i.e. homogeneous phosphorus (P) deficiency vs. heterogeneous P efficiency) among soil layers in combination with four N supply treatments in a one-year pot experiment. These N supply treatments were: (1) Homogeneously high N along the soil profile (HHH); (2) high N-high N-low N (HHL); (3) low N-low N-high N (LLH); (4) low N-low N-on side with N addition and the other side without N supply (LLH/L).Important findings This study indicated that localized N supply treatment did enhance the growth of P. massoniana, and this enhancement mainly happened in the pattern of N applied to deep soil. The results showed: 1) Compared to the homogeneous low P condition, there were increase in the growth traits and root parameters of P. massoniana under heterogeneous low P condition. Particularly, the root length and root surface area under the heterogeneous P deficiency condition were 1.95 times and 2.11 times higher than that subjected to the homogeneous P deficiency. 2) Localized N supply treatment affected seedling growth, and there was a significant interaction among N supply pattern and P condition. In compared with homogeneous N supply treatment, the height, basal diameter and dry weight of seedlings increased significantly by localized N supply treatments (LLH and/or LLH/L) under both two P deficiency conditions. But when the seedlings parameters were enhanced under homogeneous P deficiency, they were inhibited under heterogeneous P deficiency subjected to HHL. 3) Within the two P conditions, LLH and LLH/L stimulated root proliferation significantly, and root parameters were significantly enhanced under the heterogeneous P deficiency condition. Specifically, the root length and root surface area subjected to LLH/L rather than HHH were significantly enhanced by 29.2% and 32.3%, respectively. However, the length and surface area of the roots were suppressed by HHL treatment. 4). There were significant differences in response to different N supply treatments among P. massoniana families Seedlings in the families of 49, 52, and 57 responded to the localized N supply treatments with increased root proliferation, which enhanced seedling dry mass. On the other hand, the seedling growth in the family of 25 were stimulated by N and (or) P concentration, while the response of seedlings in the family of 1 to local nitrogen supply was relatively slow and exhibited growth retardation.     

小麦幼苗根系形态与反复干旱存活率的关系

以35个不同栽培类型的小麦品种（系）作为试验材料,根据其6叶幼苗的根系形态性状进行聚类分析,供试材料的根系类型分为3种：大根系、小根系和中间型根系。具有中间型根系的材料反复干旱存活率最高,这些材料的根系特点是单株根数7－8．5条,最大根长20-22cm,根总干重44－48mg,其中10cm以下根干重占36％－45％,根冠比范围在0.22-0.24。一些水地栽培的育成品种苗期抗旱性较强,旱地栽培的育成品种苗期抗旱性差异较大,个别旱地栽培的地方品种在土壤水分胁迫条件下反而比在正常水分条件下的根系发育更好,可能是长期适用干旱条件的结果。     

Genetic Analysis of Root Growth in Rice Seedlings Under Different Water Supply Conditions

To understand the genetic background of root growth of rice (Oryza sativa L.) seedlings under different water supply conditions, quantitative trait loci (QTLs) and epistatic effect on seminal root length, maximum adventitious root length, adventitious root number, total root dry weight and ratio of root to shoot were detected using molecular map including 103 restriction fragment length polymorphism (RFLP) markers and 104 amplified fragment length polymorphism (AFLP) markers mapped on a recombinant inbred line (RIL) population with 150 lines derived from a cross between an lowland rice IR1552 and an upland rice Azucena in both solution culture (lowland condition) and paper culture (upland condition). Six QTLs and twenty-two pairs of epistatic loci for the four parameters were detected. Three QTLs detected for maximum adventitious root length in solution culture (MARLS), total root dry weight in both solution culture and paper culture (TRDWS and TRDWP) accounted for about 20%, 23% and 13% of the total variations, respectively. Only epistatic loci were found for maximum adventitious root length and adventitious root number in paper culture (MARLP and ARNP), and for ratio of root to shoot in both paper and solution culture (R/SP and R/SS), which accounted for about 12%-61% of the total variations in the parameters, respectively. No identical QTL or epistatic loci were found for the parameters in both solution and paper culture. The results indicate that there is a different genetic system responsible to root growth of rice seedlings under lowland and upland conditions and epistasis might be the major genetic basis for MARLP, ARNP, R/SP and R/SS.     

硫水平对玉米氮、硫代谢特性及根系活性的影响

通过Hoagland营养液水培玉米,定量研究了供S水平对玉米根系活性和植株S、N代谢特性的影响．当玉米缺S时。玉米根系活性和叶片硝酸还原酶(NR)活性显著降低,植株冠／根比增大;根系与地上部对S、N的吸收均减少。S在根系和新生叶中分配相对减少、在衰老叶和茎鞘中分配相对增多;N在根系中分配增多,新生叶和完全展开叶中分配相对减少;植株蛋白质、蛋白氮、蛋白硫、无机硫的含量均显著降低,非蛋白氮比率增多,无机硫占总S的比率变小,全N／全S比增大;蛋白质中的N／S比在地上部无显著变化。而在根系中显著增大;根系对S缺乏的反应更为敏感．研究表明。缺S植株蛋白质含量与NR活性之间呈极显著正相关;S的缺乏或过量均影响玉米的N、S代谢;以根系作为S素营养诊断器官。以N／S比或无机S／全S比作为诊断指标较灵敏。正常条件下其数值分别为10．7和0．302．