不同株型高产玉米蒸腾作用的研究

在夏玉米亩产吨粮的研究中,测定了平展型玉米各单40和紧凑型玉米掖单6号大喇叭口期和吐丝期不同叶位不同密度的蒸腾速率(Tr)及其日变化.结果看出:鲁单40的Tr高于掖单6号,大喇叭口期Tr高于吐丝期.玉米前期上部展开或即将展开的叶Tr较高,后期中部和上部较高.Tr的日变化为单峰曲线,中午最高.增加种植密度使Tr减少,鲁单40玉米的Tr受密度影响较大.     

不同基因型玉米品种耐密性数学表达研究

随着玉米生产水平的不断提高 ,玉米的种植密度越来越大 ,高产再高产给玉米品种的耐密性提出了更高的要求。所谓的品种耐密性就是指某个玉米品种在较大群体下具有的较高的单株生产力 ,且对不同群体密度反应的迟钝性。近年来 ,有关玉米耐密性的研究较多 ,但对如何将耐密性进行数学量化 ,以便对玉米品种的耐密性进行正确评价 ,目前尚研究不多 ,本文试图通过 4个不同基因型玉米品种的耐密性的量化研究 ,给玉米育种及高产栽培提供理论依据。1　材料和方法1 .1　供试品种选择 4个不同基因型玉米品种 :东岳 2 1号、掖单 1 3号、掖单 4号、鲁单 50号…     

不同玉米品种对南方锈病的抗性比较

采用田间自然病圃对19个河南省主栽玉米品种进行了抗南方锈病比较。结果表明：玉米品种间对南方锈病抗性差异明显,其中鲁单981、蠡玉16、DH601抗性较强;郑单958、鲁单9002、粟玉2号对锈病抗性较差;其余玉米品种对锈病的抗性水平居中间类型。     

施磷量对玉米产量及叶片部分酶活性的影响

选用天津市主推玉米品种中单509,设5个施磷水平,测定不同生育期叶片的硝酸还原酶(NRase)、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性及玉米产量。结果表明,随施磷量的增加,玉米产量先升高后下降,呈单峰曲线变化,施纯磷量在75 kg/hm~2时中单509产量达到最大。随施磷量的增加,叶片SOD、POD、CAT、硝酸还原酶活性均先上升后下降,呈单峰曲线变化。施纯磷量在105 kg/hm~2时,大喇叭口期叶片POD活性最高;施纯磷量在75 kg/hm~2时,抽雄期叶片SOD活性和CAT活性、拔节期叶片硝酸还原酶活性最高。不同施磷量处理对玉米叶片的酶活性及产量有一定影响,增施适量磷肥有利于玉米叶片的氮代谢和玉米产量提高。     

施钾量对玉米产量及叶片部分酶活性的影响

选用天津市主推玉米品种中单509,设置5个施钾水平,测定不同生育期叶片的硝酸还原酶(NRase)、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性及玉米产量。结果表明,随着施钾量的增加,玉米产量先升高后下降,呈单峰曲线变化,当施纯钾量在67.50 kg/hm2时,产量达到最大。随着施钾量的增加玉米叶片SOD活性、POD活性、CAT活性都是先升高后下降,呈单峰曲线变化,SOD和POD活性以施纯钾量为67.50 kg/hm2时抽雄期为最高,CAT活性以施纯钾量为90.00 kg/hm2时抽雄期为最高,硝酸还原酶活性以施纯钾量为67.50 kg/hm2时拔节期达最高。不同施钾量处理对玉米叶片的酶活性及产量有显著的影响,施用适量的钾肥有利于玉米叶片的氮代谢和产量的提高。     

不同株型玉米光能利用状况的研究

利用美国LI－188B辐射量子照度仪,对掖单4号、掖单13和沈单7号3种不同株型玉米叶片及群体光能利用状况进行了测定研究,结果表明3种玉米品种叶片辐射吸收系数存在一定差异：掖单4号为0.75,掖单13为0.73,沈单7号为0.71。利用三次样条函数模拟了玉米群体中太阳总辐射及反射辐射分布状况,给出了不同品种玉米群体中吸收辐射随高度分布特征,发现在玉米叶片光合能力最大的80～180cm处,掖单4号吸收辐射最大,因而从理论上证实了紧凑型玉米品种光能利用效率最高,与当前高产实践相一致,并为玉米高产提供了理论指导。     

玉米种子携带MDMV的检测

采用苗期症状观察、ELISA和回接试验测定了几个玉米品种种子携带玉米矮花叶病毒(MDMV)的情况，并对采自河北承德制种田的玉米品种掖单2号种子带毒部位进行了ELISA检测和侵染活性的生物学测定。结果表明，各部位携带病毒及其侵染活性差异显著。其中种表携带较多的丧失了侵染活性的MDMV；种皮携带病毒的侵染活性较低；胚乳带毒率和其侵染活性均较高；胚不带毒。此外，种子质量不同，其带毒情况也存在很大的差异。由此证明，种子处理和精选可以作为玉米矮花叶病防治的主要措施之一．     

夏玉米品种盐碱胁迫耐受能力评价

以郑单958为对照,在盆栽条件下,对土壤进行对照(非盐碱土)、轻度盐碱(0.188%)、中度盐碱(0.268%)3种处理,对12个黄淮海地区主推夏玉米品种分别进行萌发期和苗期的盐碱耐性评价。结果表明,品种间发芽率和发芽势对盐碱胁迫敏感程度存在显著差异,其中,承玉10在中度盐碱条件下发芽率和发芽势相对值分别比郑单958高21%和43%。与对照土壤相比,在轻度盐碱和中度盐碱胁迫条件下,鲁单818根表面积、根体积、总根长均有明显地增加,金海5号、登海605、德利农318则显著下降。在中度盐碱胁迫条件下,济丰96和郑单958叶片MDA含量和SOD活性均有所下降,鲁单818的POD活性和可溶性蛋白相对值均最高。根据轻、中度盐碱土壤下7个指标隶属函数值综合评价,鲁单818、承玉10为早期耐盐碱品种,济丰96、德利农318、浚单20为早期不耐盐碱品种,其他为早期中等耐盐碱品种。     

氮肥施用量对春玉米光合作用关键酶活性和光合速率的影响

以不同品种春玉米为试验材料,研究了氮肥施用量对春玉米功能叶片光合作用关键酶活性和光合速率的影响。结果表明,氮肥施用量对RuBP羧化酶活性、PEP羧化酶活性和光合速率有明显影响,不同品种的表现不尽相同,东甜4号和东农早粘以N100处理最为适宜,东农248和四单19则以N200处理较好。氮肥用量与RuBP羧化酶活性、PEP羧化酶活性呈现阶段性相关,不同品种相关程度不同。     

种植密度对不同粒型玉米品种子粒灌浆进程、产量及品质的影响

以鲁单981(大粒型)、泉星2101(小粒型)两个不同粒型玉米品种为材料,研究了3种种植密度对玉米子粒灌浆进程、产量及品质的影响。结果表明,增加种植密度可提高单位面积玉米产量,促进大粒型品种LD981灌浆前期单粒重的提高,但均不利于大粒型和小粒型品种在灌浆后期维持较高的粒重。种植密度对玉米单粒重的影响主要是缓增持续期、快增期灌浆速率、缓增期灌浆速率和灌浆持续期所致,而平均灌浆速率对其影响较小。随着密度的增加,可溶性总糖含量逐渐升高,直链淀粉含量先升高后降低,但支链淀粉、总淀粉、粗蛋白和粗脂肪含量表现为先降低后略有升高。     

Effects of sulphur dioxide and nitrogen dioxide on shoot and root growth of Kennebec and Russet Burbank potato plants

The effects of sulphur dioxide (SO₂) and nitrogen dioxide (NO₂), singly and in combination, on the shoot and root growth of two potato cultivars sensitive to these pollutant gases were determined using rooted cuttings in controlled conditions. Plants were exposed to 0.11 ppm SO₂ and/or 0.11 ppm NO₂ for 24 hours a day for 7 or 14 days. Kennebec plants had significantly lower root fresh and dry weights after 7 days in the mixture treatments and lower root fresh weight in the NO₂ treatment. Russet Burbank plants were more sensitive to SO₂ and NO₂ than Kennebec. Russet Burbank plants had significantly reduced leaf area, and leaf, stem, and root fresh and dry weights after 7 and 14 days of mixture treatment, and the leaf to root dry weight ratio was higher than in control plants. The combination treatment and SO₂ alone resulted in visible injury on leaves of both cultivars. Changes in tissue water concentration, decreased specific leaf area and decreased root growth suggested that SO₂ and NO₂ altered plant water status and interfered with partitioning of dry matter from the leaves to other plant parts.     

青枯病对不同抗性玉米自交系叶片生理特性的影响

以对青枯病抗性不同的两个玉米自交系为材料,研究青枯病对玉米叶片过氧化物酶(POD)活性、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、叶绿素含量、可溶性蛋白含量以及电导率的影响。结果表明,接种青枯病菌后,感病自交系黄早四从14 d开始出现感病症状,抗病自交系K12HF526在30 d后才出现轻微感病症状。两个自交系对照组叶片的POD活性、SOD活性和MDA含量表现趋势一致,抗病自交系高于感病自交系。不同自交系对照组的叶片叶绿素含量一致,处理组中感病自交系明显低于抗病自交系,可能是感染青枯病导致叶绿素含量降低。抗病自交系叶片可溶性蛋白含量在接种前后差异不显著,感病自交系接种21 d后显著降低。通过电导率计算伤害率的结果表明,抗性自交系的伤害率远远低于感病自交系。     

Effects of sulphur dioxide and nitrogen dioxide on fourSolanum tuberosum L. cultivars

The effects of sulphur dioxide (SO₂) and nitrogen dioxide (NO₂), singly and in combination, on the shoot growth of four potato cultivars differing in maturity classification (Solanum tuberosum L. ‘Superior,’ ‘Norchip,’ ‘Kennebec, rs ‘Russet Burbank’) were determined in controlled conditions. Plants were exposed to 0.11 ppm SO₂ and/or 0.11 ppm NO₂ for 24 hours a day for 7 or 14 days. There were no significant differences in leaf growth of ‘Superior’ or ‘Norchip’ plants at 7 or 14 days. Stem dry weight was significantly reduced in ‘Superior’ only after 14 days in the mixture. ‘Kennebec’ and ‘Russet Burbank’ plants had significantly less leaf area, leaf fresh weight, and leaf water content after 14 days of exposure to the mixture, but there was no significant change in dry weight. Specific leaf weight was significantly increased in the mixture treated plants of both cultivars. The two earlier maturing cultivars, ‘Superior’ and ‘Norchip,’ were less sensitive to the SO₂ and NO₂ combination than the two later maturing cultivars, ‘Kennebec’ and ‘Russet Burbank’.     

二氧化硫胁迫对玉米幼苗叶片膜脂过氧化和抗氧化酶的影响

利用NaHSO₃处理玉米幼苗模拟水相SO₂胁迫,比较分析了BT-1(抗)、N6(感)自交系经NaHSO₃胁迫后细胞膜脂过氧化和几种抗氧化酶活性的动态变化。结果表明：随着水相SO₂胁迫时间的延长,高感系N6叶片中丙二醛(MDA)含量和H₂O₂积累量比高抗系BT-1显著增加;抗、感系中抗氧化酶超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性都有明显的增强,而过氧化氢酶(CAT)的活性呈显著下降趋势。说明H₂O₂的积累导致玉米叶片膜脂过氧化加剧,SOD和APX在玉米遭受SO₂胁迫中起着重要的保护作用。     

外源硫诱导玉米镉胁迫耐性的生理机制研究

采用水培试验,研究根部施加外源SO_4~(2-)对Cd胁迫下玉米幼苗相关关键生理指标的影响,并分析Cd在玉米组织和亚细胞分布情况,探究外源硫S对玉米响应镉(Cd)胁迫的影响机制。结果表明,外源SO_4~(2-)处理,可显著降低Cd胁迫下玉米叶片与根中的丙二醛含量、相对电导率和抗氧化酶(SOD、CAT)活性。同时,根中抗坏血酸、非蛋白硫醇、植物螯合素含量在外源SO_4~(2-)处理后显著上升,在叶片中的变化不显著。外源SO_4~(2-)处理可降低玉米叶片中Cd含量,提升在根中的含量。根细胞壁和液泡中的Cd含量显著上升,从而减少Cd向地上部分的运输量。根细胞液泡膜中Cd运输专一性基因HMA3在外源SO_4~(2-)处理后,表达水平显著增强。因此,外源S可以通过提升Cd胁迫处理下玉米根细胞壁中Cd含量和抗坏血酸的保护作用,同时促进液泡的区室化作用,降低Cd向玉米地上部位的转运,以增强玉米对Cd胁迫的耐受性。     

NaCl和Na2SO4胁迫对玉米幼苗渗透调节物质含量的影响

研究了NaCl和Na₂SO₄胁迫对玉米幼苗电解质渗漏、根系活力及脯氨酸、可溶性糖、可溶性蛋白等渗透调节物质含量的影响。结果表明，玉米在NaCl作用下其电解质渗漏、根系活力及渗透调节物质含量的变化和Na₂SO₄胁迫相似，电解质渗漏、根系活力及渗透调节物质含量均随着盐浓度的增加而加剧。NaCl胁迫下增幅大于Na₂SO₄胁迫，表明NaCl胁迫对玉米幼苗的伤害大于Na₂SO₄胁迫。     

玉米低钾耐性性状的主基因+多基因遗传分析

应用植物数量性状主基因+多基因混合遗传模型多世代联合分析方法,以玉米缺钾症状叶片数为指标,对1个耐低钾玉米自交系T和2个低钾敏感玉米自交系S1和S2配制成的2个组合的P1、P2、F1、B1、B2和F2世代进行遗传分析,研究明确玉米耐低钾性状的遗传机制。结果表明,玉米低钾耐性遗传在2个组合中都由1对加性+加性-显性多基因控制;主基因遗传率(F2)平均为60.43%,多基因遗传率(F2)平均为15.35%;T×S1组合的遗传变异占表型变异值为80.20%,T×S2组合的遗传变异占表型变异值为71.35%,表明耐低钾性状以主基因遗传为主。育种应用上可以在低世代进行这一目标性状的选择。     

株行配置对南疆冬小麦籽粒灌浆特性及产量的影响

为了探究适宜南疆冬小麦种植的株行配置模式,通过田间小区试验,研究了15 cm×1.7 cm、12.5 cm×2 cm、10 cm×2.5 cm、7.5 cm×3.3 cm、5 cm×5 cm共5个行、株距配置模式下2个穗型冬小麦品种(新冬22号和新冬50号)籽粒灌浆特性,用Logistic方程拟合籽粒灌浆过程,对南疆冬小麦籽粒灌浆特征参数进行了分析。结果表明,随着行距缩小,多穗型品种新冬22号达到最大灌浆速率的时间先推迟后提前,受快增期灌浆速率的影响,最大灌浆速率、平均灌浆速率均先降低后升高,千粒重先降低后增加;大穗型品种新冬50号达到最大灌浆速率时间随行距缩小而推迟,受渐增期、快增期、缓增期灌浆速率的影响,最大灌浆速率、平均灌浆速率呈降低趋势,千粒重逐渐降低。随着行距缩小、株距扩大,在未发生倒伏的情况下,两个品种的有效穗数和产量呈增加趋势。南疆400万株·hm~(-2)种植密度条件下,冬小麦5 cm×5 cm模式为最佳株行配置模式,但多穗型品种存在倒伏的风险。     

甲基磺酸乙酯(EMS)对玉米自交系诱变效应的研究

用化学诱变剂甲基磺酸乙酯处理玉米自交系082的种子,研究了该诱变剂对玉米的诱变效应.结果表明:甲基磺酸乙酯对玉米自交系种子是一种有效的化学诱变剂,在M1代引起了较大的生理损伤和生物学效应,M2代质量性状未发生明显变异,但株高、穗位高、茎周长和穗上叶片长等数量性状出现了较高的突变频率,其中株高的负突变增加明显。     

Plant population density,row spacing and hybrid effects on maize canopy architecture and light attenuation

Light attenuation within a row crop such as maize is influenced by canopy architecture, which has to be defined in terms of the size, shape and orientation of shoot components. Cultural practices that improve the efficiency of light interception affect canopy architecture by modifying such components. Our objectives were to: (i) determine the nature and timing of leaf growth responses to plant population and row spacing; (ii) analyze light attenuation within fully developed maize canopies. Field experiments were conducted at Pergamino (33°56′S, 60°34′W) and Salto (34°33′S, 60°33′W), Argentina, during 1996/1997 and 1997/1998 on silty clay loam soils (Typic Argiudoll) that were well watered and fertilized. Four maize hybrids of contrasting plant type were grown at three plant populations (3, 9 and 12 plants m⁻²) and two row spacings (0.35 and 0.70 m). Plant population promoted larger changes in shoot organs than did row spacing. As from early stages of crop growth, leaf growth (V₆–V₈) and azimuthal orientation (V₁₀–V₁₁) were markedly affected by treatments. Modifications in shoot size and leaf orientation suggest shade avoidance reactions, probably triggered by a reduction in the red:far-red ratio of light within the canopy. An interaction between hybrid and plant rectangularity on leaf azimuthal distribution was determined, with one hybrid displaying a random azimuthal leaf distribution under most conditions. This type of hybrid was defined as rigid. The other hybrids showed modified azimuthal distribution of leaves in response to plant rectangularity, even at very low plant populations. These hybrids were defined as plastic. Once maximum leaf area index (LAI) was attained light attenuation did not vary among hybrids and row spacing for plant populations ≥9 plants m⁻² (k coefficient: 0.55 and 0.65 for 9 and 12 plants m⁻², respectively). A more uniform plant distribution increased light attenuation (k coefficient: 0.37–0.49) only when crop canopies did not reach the critical LAI.