小麦孕穗期耐湿性的形态指标探讨

对14个小麦品种连续3年进行孕穗期耐湿性鉴定，结果表明：1）处理结束后15天左右各品种的叶片衰变情况表现出极大的差异；2）主茎绿色叶片的湿害指数分别与主穗结实粒数和单株粒重的湿害指数呈极显著相关；3）品种耐湿表现主要由品种本身的遗传特性所支配，因此叶片枯衰程度可以作为简易的鉴定指标。     

甘蓝型油菜耐湿性的初步评价和主成分分析

以发芽种子缺氧处理后幼苗耐湿性状为指标,初步评价了60份不同来源甘蓝型油菜耐湿性,并对各指标进行主成分分析和二维排序分析。结果表明：种子缺氧处理严重抑制油菜幼苗的生长,不同甘蓝型油菜耐湿性差异明显且存在广泛的遗传变异;相关分析表明,相对活力指数与相对成苗率、相对根长、相对茎长、相对鲜重、相对含水量呈极显著正相关,与电导率呈极显著负相关。主成分分析筛选出幼苗活力因子、幼苗恢复生长因子、细胞膜稳定性因子等3个对耐湿性贡献较大的主成分,它们对耐湿相关信息的累积贡献率达87.33%。根据相对活力指数大小和二维排序一致结果筛选出1份来自重庆和3份来自德国的强耐湿性甘蓝型油菜品种。     

甘蓝型油菜耐湿性初步评价和主成分分析

以发芽种子缺氧处理后幼苗耐湿性状为指标,初步评价了60份不同来源甘蓝型油菜耐湿性,并对各指标进行主成分分析和二维排序分析.结果表明:种子缺氧处理严重抑制油菜幼苗的生长,不同甘蓝型油菜耐湿性差异明显且存在广泛的遗传变异;相关分析表明,相对活力指数与相对成苗率、相对根长、相对茎长、相对鲜重、相对含水量呈极显著正相关,与电导率呈极显著负相关.主成分分析筛选出幼苗活力因子、幼苗恢复生长因子、细胞膜稳定性因子等3个对耐湿性贡献较大的主成分,它们对耐湿相关信息的累积贡献率达87.33%.根据相对活力指数大小和二维排序一致结果筛选出1份来自重庆和3份来自德国的强耐湿性甘蓝型油菜品种.     

我国三熟制早熟油菜品种产量构成特点及育种对策

为提高三熟制地区油菜育种效率,本文研究了三熟制地区不同熟性油菜农艺性状对产量的影响。以2016-2020国家冬油菜品种区试中衡阳和宜春地区试验结果为基础数据,利用相关分析及通径分析研究了两个区域的油菜品种产量构成特点。结果发现,中熟组和早熟组株高、有效分枝数、菌核病发病率、病情指数、单株有效角果数、每角粒数、千粒重、密度、全生育期、含油量及产量差异显著。中熟油菜每角粒数、密度、菌核病抗性与产量呈极显著正相关,菌核病发病率、病情指数、生育期与产量极显著负相关,密度对产量的直接影响最大。早熟油菜株高、有效分枝数、单株有效角果数、每角粒数、密度、含油量与产量极显著正相关,菌核病发病率与产量显著负相关;对产量直接影响最大的是有效分枝数。认为育种策略中,两种油菜都应选育抗菌核病和适合高密度种植的品种,中熟油菜应提高单株有效角果数,而早熟油菜要增加有效分枝数。     

PEG-6000模拟干旱胁迫对不同甘蓝型油菜品种 萌发和幼苗生长的影响

采用10％聚乙二醇（PEG-6000）模拟干旱胁迫的方法，研究其对14个甘蓝型油菜品种发芽期生理生化性状的影响。结果表明，PEG-6000模拟干旱胁迫后，幼苗的相对活力指数在0.32－0.79之间，14个品种的平均相对活力指数为0.49。干旱胁迫后，14个油菜品种的平均苗高比对照降低40.68％，平均单株鲜重比对照降低34.2％，平均成苗率比对照降低18％。但干旱胁迫对根系生长的影响差异不显著。PEG-6000模拟干旱胁迫后，幼苗丙二醛（MDA）、可溶性糖、脯氨酸、可溶性蛋白的含量和电导率均比对照极显著提高，丙二醛的平均含量比对照提高96.7％，可溶性糖平均含量比对照提高75.0％，脯氨酸平均含量比对照增加2204.9％，可溶性蛋白的平均含量比对照增加56.2％，平均电导率比对照增加34.8％。在各种指标中，相对活力指数较为直观、综合地反映了发芽和生长性状，可作为油菜发芽期抗旱鉴定的主要指标。     

PEG胁迫下甘蓝型油菜品种（系）种子发芽耐旱性鉴定

以10%（w/v）PEG6000做渗透介质模拟干旱条件,对不同来源的甘蓝型油菜(Brassica napus L.)品种（系）进行干旱胁迫下种子发芽鉴定,分析油菜种子发芽耐旱性的遗传多样性。结果表明：干旱胁迫下,部分材料处理与对照的发芽性状有显著性差异,81个甘蓝型油菜材料的平均苗高处理比对照低36.5％,平均鲜重处理比对照低31％,成苗率降低11.1％。甘蓝型油菜品种（系）耐旱性有较大遗传差异,幼苗活力指数的变异幅度为19％－81%,平均活力指数为55％。相关分析表明,活力指数与胁迫下的发芽性状达极显著正相关,可以作为油菜种子发芽耐旱的综合指标。根据活力指数,将81个油菜资源划分为强,中,弱三个耐旱等级,并筛选到30295,30253,中双6号,30703,30296,30290,30704,中油杂9号,德油4号等一批耐旱遗传资源。     

甘蓝型油菜耐湿种质资源的快速筛选

将不同来源甘蓝型油菜种质资源种子发芽60h,取露白种子进行密闭水淹缺氧处理12h后转入砂床继续 发芽,未作缺氧处理的露白种子作为对照, 6d后测定发芽相关性状,根据发芽性状差异评价油菜耐湿性。结果表 明,与对照相比,缺氧处理对油菜幼苗生长具有显著的抑制作用:平均相对根长为24. 7% ,平均相对茎长和鲜重分 别为59. 7%、69. 1% ,平均相对成苗率为79. 4% ,平均相对活力指数(RV I)为0. 49。相关分析表明, RV I、电导率、相 对成苗率、相对根长、相对茎长、相对鲜重等各发芽相关性状均相互呈极显著相关,其中相对活力指数可以全面评 估甘蓝型油菜在缺氧胁迫后的恢复生长能力,而电导率可以作为耐湿材料高通量早期筛选的指标。不同材料RV I 呈正态分布,变幅为0. 04～0. 92,表明甘蓝型油菜种质资源耐湿性存在十分丰富的遗传差异,其中03P79 - 1、03P62 - 5、中双8号等品系(种)具有较强的耐湿性,可以作为耐湿性资源加以利用。     

湿害胁迫对发芽期芝麻的影响及耐湿性评价方法建立

为研究湿害胁迫对发芽期芝麻的影响,将7份发芽至露白的芝麻材料分别淹水处理3h、6h、9h、12h、15h和24h,继续培养5d后对电导率、死亡率、成苗率等指标进行测定。结果表明,随着胁迫处理时间的延长,电导率和死亡率不断增加,成苗率、根长和活力指数呈下降趋势,畸形苗率表现先升后降;6h～12h时,成苗率和简易活力指数急剧下降,说明淹水6h～12h是芝麻发芽期湿害的敏感时间段。31份高代品系经淹水胁迫7h、9h和12h后的发芽特性表明,9h处理时各项指标的变异系数明显大,因此,淹水9h是评价芝麻发芽期耐湿性的适宜时间,相对成苗率可作为主要评价指标。依此方法对222份芝麻种质发芽期耐湿性遗传差异的评价结果显示,极不耐湿的材料70份;不耐湿的69份;中耐43份;耐湿28份;高耐湿的12份,分别为ZZM1501、ZZM2113、ZZM2147、ZZM2208、ZZM3342、ZZM3379、ZZM3410、ZZM4780、ZZM4781、09-P65、辽品芝3号、漯芝15。     

外源海藻糖浸种对低温胁迫油菜种子萌发及幼苗生长的影响

为提高抗寒性,促进油菜种子发芽及幼苗生长,以甘蓝型油菜品种中油杂19为材料,研究外源海藻糖浸种对低温胁迫下油菜种子萌发及幼苗生长的影响,阐明外源海藻糖浸种的寒害缓解作用.结果表明,在低温处理下(10℃),油菜种子萌发受到抑制,发芽势、发芽率、发芽指数及活力指数均显著下降,平均发芽时间显著延长;种子萌发过程中异柠檬酸裂解...     

隶属函数法鉴定油菜甘芥种间杂交后代的抗旱性

在大田水分胁迫条件下,采用隶属函数值法、灰色关联度分析法结合聚类分析,研究58份甘蓝型油菜和芥菜型油菜的种间杂交后代,分析其单株产量、主花序产量和品质性状的差异。结果表明,单株分枝数和有效角果数与抗旱性显著相关,而角粒数和千粒重与抗旱性关联性较弱。在水分胁迫条件下,抗旱材料主花序的三个性状,即含油量、蛋白质含量和千粒重,在强抗、较抗、不抗材料间的差异均达到1%显著水平,且与单株产量的关联度在50%以上,其中主花序籽粒的含油量及千粒重升高,蛋白质含量降低。利用水分胁迫下三个性状的差异变化可对抗旱油菜进行初步筛选。通过筛选,获得2007M004、2007M018和2007M027三份平均隶属函数值≥0.413的抗旱材料。     

Alleviation of waterlogging damage in winter rape by application of uniconazole: Effects on morphological characteristics,hormones and photosynthesis

Oilseed rape seedlings (Brassica napus L.) treated with uniconazole were transplanted at the five-leaf stage into specially designed experimental containers, and then exposed to waterlogging for 3 weeks. Pre-treatment of rape seedlings with uniconazole significantly increased seedling height, shoot width, number of green leaves and leaf area per plant, and consequently the shoot, root, and total dry weight after waterlogging. Following waterlogging stress, the uniconazole treated plants had a significantly improved growth including plant height, length and width of leaves, number of green leaves, leaf area per plant, and canopy width at the stem elongation stage, and plant height, stem width, and root, shoot and total dry weight at the flowering stage. At harvest, uniconazole treatment increased the number of primary and secondary branches, seeds per pod, and number of effective pods in branches and in terminal raceme after waterlogging treatment. The uniconazole-induced increase in the number of pods per plant and number of seeds per pod were the two yield components responsible for the significantly greater seed and oil yields obtained from the uniconazole plus waterlogging treated plants, over either the control or waterlogged plants. Uniconazole also reduced waterlogging-induced rise in the erucic acid content of the seeds. The modification of GA₃, zeatin, ABA and ethylene levels due to pre-treatment of rape seedlings with uniconazole might have helped to delay the chlorosis and senescence induced by waterlogging. Uniconazole treatment also increased the leaf photosynthetic rates of waterlogged plants, in part, due to the changes in leaf conductance and hormone levels which ultimately affected various physiological processes.     

Rooting traits of peanut genotypes with different yield responses to pre-flowering drought stress

Water stress during the vegetative development normally is not detrimental and sometimes actually increases yield of peanut (Arachis hypogaea L.). Root growth might play an important role in response to early season drought in peanut and might result in an increase in yield. Information on the response of root characters of diverse peanut genotypes to these conditions will provide useful information for explaining mechanisms and improving peanut genotypes for exploiting positive interaction for pod yield under pre-flowering drought. The aim of this study, therefore, was to investigate the root dry weight and root length density of peanut genotypes with different yield responses to pre-flowering drought stress and their relationships with pod yield. Field experiments were conducted at the Field Crop Research Station of Khon Kaen University, Khon Kaen, Thailand during February to July 2007 and during February to July 2009. A split-plot experiment in a randomized complete block design was used. Two water management treatments were assigned as the main plots, i.e. field capacity and pre-flowering stress, and six peanut genotypes as the sub-plots. Total crop dry matter, root dry weight and root length density were recorded at 25 DAE, R5 and R7. Top dry weight and pod yield were measured at harvest and pod harvest index (PHI) was computed using the data on pod yield and biomass. Peanut genotypes were categorized into three groups based on their responses to drought for pod yield, e.g. increasing, decreasing and non-responsive groups. The genotypes of each group showed a differential response for root quantity and distribution. The increasing pod yield group had more root dry weight and root length density in the deeper soil layers during pre-flowering stress compared to the non-stress treatment. The non-responsive group showed no root response under pre-flowering drought conditions compared to the non-stress treatment. A larger root system alone without considering distribution may not contribute much to pod yield but a higher RLD at deeper layers may allow plants to mine more available water in the sub-soil. However, as yield is a complex trait, several mechanisms may be involved. The increasing pod yield group also had the ability to maintain a high PHI.     

Seed Treatment with Uniconazole Powder Improves Soybean Seedling Growth under Shading by Corn in Relay Strip Intercropping System

The relay strip intercropping system of wheat-corn-soybean is widely used in southwest China. However, it is hard to obtain a stable production of soybean with this system, since soybean plants grow under shading by corn; the stems are thinner and susceptible to lodging. We examined the effects of seed treatment with uniconazole powder (0, 2, 4 and 8 mg kg-¹ seed) on the growth of soybean seedlings under relay strip intercropping, some morphological characteristics and yield. The seedling height, first internode length, cotyledonary node height and leaf area per plant were decreased, while the stem diameter, root dry weight, shoot dry weight, root volume, leaf greenness and root to shoot dry weight ratio were increased by uniconazole treatment. The root vigor and root active absorption area were also increased significantly by uniconazole treatment. Moreover, 2 and 4 mg kg-¹ uniconazole powder treatment increased shoot dry weight, number of pods per plant, number of seeds per pod and seed yield significantly. Thus, the results suggested that seed treatment with uniconazole powder at a suitable concentration can improve soybean seedling growth, resist the lodging and also increase the seed yield under shading by corn in relay strip intercropping system.     

干旱胁迫对不同抗旱性小麦种子萌发及幼苗根芽生物量分配的影响

为探讨冬小麦种子萌发期抗旱性与幼苗生物量分配的关系,以小麦抗旱型品种长旱58和干旱敏感型品种漯麦18为材料,采用聚乙二醇(PEG-6000)模拟干旱胁迫的方法,测定和分析了干旱胁迫后小麦种子发芽率、幼苗根冠比、叶绿素含量等16个指标的变化。结果表明,干旱胁迫后,长旱58种子发芽率无明显变化,漯麦18种子发芽率显著下降。干旱胁迫下长旱58种子发芽势、发芽指数、活力指数和干物质转移量显著大于漯麦18,平均发芽时间显著小于漯麦18,长旱58幼苗根、芽的长度和干重及总干重均显著高于漯麦18。干旱胁迫显著增加漯麦18幼苗根冠比,对长旱58萌发第五和第七天的幼苗根冠比无显著影响。干旱胁迫显著降低漯麦18幼苗叶绿素含量,对长旱58无显著影响。由于小麦萌发期幼苗干物质累积取决于种子中营养物质的转移和呼吸消耗,因此推测种子营养物质的快速转移和低呼吸消耗有助于提高小麦萌发期的抗旱能力,促进干旱胁迫下种子萌发和幼苗生长。     

Al^3＋胁迫下的野生狼尾草种子萌发研究

通过种子萌发试验,研究狼尾草萌发期对铝胁迫的耐受性。结果显示,Al^3＋胁迫浓度与狼尾草发芽势、发芽指数、活力指数、芽长之间存在极显著负相关性;Al^3＋浓度超过4000μmol／L,根长显著下降,随着 Al^3＋浓度的升高,根长维持在2 mm 左右。研究表明狼尾草是一种强耐酸铝胁迫的种质资源,耐铝狼尾草筛选浓度确定为 Al^3＋浓度2000μmol／L。     

棉花秸秆浸提液对小麦种子萌发及幼苗生长的化感效应

为了解棉花秸秆对小麦生长发育的化感效应,按每克秸秆粉碎物10 mL水的比例浸提制备母液(浓度记为10％),以小麦品种扬麦13为材料,研究不同浓度棉花秸秆浸提液对小麦种子萌发和幼苗生长的影响.结果表明,浓度低于7.0％的棉花秸秆浸提液延迟了小麦种子发芽时间,但不影响发芽率;浓度高于7.0％的浸提液不仅延迟了发芽时间,而且降低了发芽率.浸提液对小麦幼苗地上部和根系生长的影响差异较大.浓度低于1.0％的浸提液对根系生长影响较小,高于此浓度水平则抑制根系伸长和根表面积增大,增加根系膜脂过氧化程度,降低根系活力,抑制根系吸收水分和养分及其向地上部的运输能力;4.0％的浸提液促进了小麦幼苗地上部对氮、磷、钾和水分的吸收,当浸提液浓度继续升高,促进作用逐渐减弱,直至表现为抑制作用.浸提液中总酚酸含量较高,10.0％的浸提液中总酚酸含量达到124.0 mg· L-1,且总酚酸含量与种子萌发相关指标(发芽率、发芽势和发芽指数)、整株鲜重、根冠比、根系含水量、总根长、根表面积和根系活力均呈显著负相关,与根系氮、磷、钾含量、根平均直径和丙二醛含量呈显著正相关.由此推测,棉花秸秆的化感效应可能与浸提液中总酚酸含量有关,影响小麦种子萌发和幼苗对水分及养分的吸收与运输是其化感效应的主要表现.     

不同大豆品种对氮肥反应的差异

5个不同大豆品种的盆栽试验结果表明,品种间生物产量和籽粒产量的差异,尤其在高氮条件下的差异更明显,而籽粒粗蛋白含量差异在低氮条件下较明显;大豆品种间根系鲜重、根系活力、叶绿素含量的差异与产量差异趋势基本一致。根鲜重、根活力和叶绿素含量与生物产量和籽粒产量呈显著或极显著正相关。宁镇1号和87A6根系发达、活力强,叶绿素含量和氮素利用率、收获指数及产量较高。     

Simultaneous selection for seed and forage production in cocksfoot (Dactylis glomerata): application of drought tolerance and susceptibility indices

An experiment was conducted to estimate drought tolerance of some cocksfoot genotypes based on seed and forage yield and related indices (including tolerance index, mean productivity, geometric mean productivity, reduction percentage index, stress tolerance index and stress susceptibility index) and to identify relationships between measured traits. Twenty‐five genotypes were evaluated in the field under control and drought‐stress environments over 2 years. The results revealed a high variation for seed yield and forage yield and the measured indices under both moisture conditions. No correlation was observed between seed yield and forage yield under the control treatment, but this correlation was positively significant under the water‐stress treatment. Drought‐tolerant and susceptible genotypes were identified based on seed and forage yield performance. Genotypes 2, 4 and 7 had high seed yield, while genotypes 7 and 10 had high forage yield under both stressed and non‐stressed conditions and were identified as the most tolerant genotypes in each category. The results also revealed that genotypes 1, 2, 4, 6, 7, 8 and 24 had relatively high seed and forage yield in both control and drought‐stressed conditions. These genotypes can be used for further studies to improve both seed and forage yields concurrently.     

壳聚糖对玉米幼苗生长及生理生化活性的影响

采用浸种实验,研究不同分子量壳聚糖对玉米种子萌发、幼苗生长及生理生化活性的影响。结果表明,5种壳聚糖均能显著提高玉米种子的发芽率、发芽势、发芽指数、活力指数和幼苗的根长、芽长和株鲜重,提高幼苗的叶绿素含量和可溶性蛋白含量,增加幼苗的根系活力,有效诱导超氧化物歧化酶(SOD)和过氧化物酶(POD)的表达,显著提高酶活性。平均分子量5 000的壳聚糖对种子萌发和幼苗生长促进效果较好,分子量为3 000的壳聚糖对幼苗生理活性及酶活力提高最大。     

小麦种子萌发期抗早衰鉴定指标的初步研究

为了探索小麦抗早衰性的早期鉴定指标,采用种子萌发试验比较了不同抗早衰类型的33个小麦(Triticum aestivum L.)品种(系)萌发种子的芽长、胚芽鞘长、主胚根长、种子根数、根系活力、种子贮藏物质转运率、总鲜重、总干重、根芽干重、干物质含量等指标与抗早衰性之间的关系。结果表明,萌发种子的芽长、胚芽鞘长、主胚根长、种子根数、根系活力、总鲜重及根芽干重等7项指标均与小麦抗早衰性无明显相关性;萌发种子的总干重、干物质含量与小麦抗早衰性有部分相关性,但不能准确区分抗早衰型和典型早衰型品种(系);种子贮藏物质转运率能较好区分不同抗早衰类型的小麦品种,可作为小麦种子萌发期抗早衰性的鉴定指标。