种衣剂类型对花生种子萌发和幼苗生长的影响

采用室内培养试验,选用不同浓度壳聚糖和不同种类的微量元素（铁、锌、铜、锰）,对花生种子进行包衣处理,明确不同浓度壳聚糖和微量元素种类对花生种子发芽势、发芽率、幼苗生物量、根与子叶残留物质量的影响。结果表明,壳聚糖浓度对花生种子的发芽势和发芽率有影响,其浓度过高过低均降低种子发芽率和发芽势。微量元素对花生种子的发芽率、发芽势和幼苗生物量积累均为促进作用,且效果明显。     

粒重对花生幼苗素质及内含物变化的影响

以四个花生品种种子为试材,采用水培方法,研究了粒重对花生种子萌发后幼苗农艺性状及内含物变化的影响。结果表明,同一品种不同粒重对花生种子萌发期胚芽、胚轴和根长度的影响存在差异但不显著,其幼苗干重间亦无显著性差异,而其残留物间存在显著性差异,表现为大粒种子中粒种子小粒种子。不同粒重种子幼苗根冠比值因品种的不同而存在差异,花育33、花育25和花育22根冠比值大小随粒重的变化趋势依次表现为小粒种子中粒种子大粒种子,而花育20大粒种子幼苗根冠比值最大,小粒种子次之,中粒种子最小。同一品种不同粒重种子幼苗建成后的物质转移量间差异不显著,但其物质转移率间存在显著性差异,其变化趋势为小粒种子中粒种子大粒种子。可溶性淀粉和可溶性蛋白质含量均以小粒种子的叶片和残留物中较高,而可溶性糖含量则以大粒种子叶片、根和子叶残留物中较高。     

橡胶叶水浸提液对花生幼苗早期根系形态及其生理特性的影响

为深入理解橡胶树的化感抑制作用,采用适当浓度的橡胶叶水浸提液处理刚萌动的花生种子10 d,测定花生幼苗早期根系形态及其生理指标。结果表明:橡胶叶水浸提液能显著降低花生幼苗胚根长度、苗高、根鲜重、地上部鲜重以及根冠比,对根生长的抑制作用比地上部强烈;能显著降低根系总长、根表面积、根体积和根尖数,但对根平均直径有轻微的促进作用,与对照相比,差异不显著;能显著降低根系SOD、POD、CAT活性、可溶性蛋白质、可溶性糖、脯氨酸含量以及根系活力,却明显增加根系MDA含量和相对电导率。说明橡胶叶水浸提液可通过破坏花生幼苗的抗氧化防御机制,降低其渗透调节能力,减少根系的吸收面积,抑制根系的吸收活性来抑制花生幼苗的生长。     

盐胁迫对花生植株形态建成及物质积累的影响

通过不同浓度盐胁迫对花生种子萌发出苗、幼苗植株形态建成和物质积累的影响,探究各指标与盐胁迫浓度间的关系,为建立花生品种耐盐评价体系及指导盐碱地花生生产提供理论依据。通过选用豫花15、花育25、阜花11和冀花5号四个花生品种,设0、0.15%、0.30%、0.45%、0.50%和0.55%六个盐胁迫浓度,采用盆栽土培试验方法模拟自然盐碱地状况,研究不同浓度盐胁迫对花生出苗、幼苗形态和物质积累的影响。盐胁迫抑制花生出苗,阻碍幼苗植株形态建成和物质积累,且存在剂量效应。随盐胁迫浓度的增加,出苗时间延长,出苗率降低,胚轴伸长,子叶物质消耗减少,物质积累减少。显著性分析结果表明,不同盐胁迫浓度间出苗时间、出苗率、株高、主茎高、主根长、根体积、叶片数、子叶鲜干重、地上部鲜干重、地下部鲜干重和植株鲜干重等15个指标差异显著;品种间主根长、根体积、叶片数、子叶鲜重、地下部鲜重、地上部干重、地下部干重和植株干重等8个指标差异显著;根体积、叶片数、植株鲜重、地上部干重和植株干重等5个指标浓度与品种互作效应差异显著。各品种在同一指标不同盐胁迫浓度或相同胁迫浓度不同指标间的耐盐性存在差异。阜花11耐盐性相对较强而豫花15相对较弱。各指标耐盐指数与盐胁迫浓度间可用Logistic回归方程y=k/(1+exp(a+bx))进行拟合,其决定系数在0.3718~0.9436之间,均达显著或极显著水平,可有效表达花生生育前期相关耐盐指标与土壤盐含量间的量化关系。花生出苗的盐含量阈值为0.45%,超过此浓度不能出苗。相对出苗时间、相对株高、相对主茎高、相对根体积、相对叶片数、相对子叶干重、相对地上部鲜干重、相对地下部鲜干重和相对植株鲜干重等12个指标均可作为综合评价花生品种耐盐性的理想指标。     

田间焚烧麦秆对玉米种子萌发和幼苗生长的影响

采用水培法研究了麦秆焚烧后的土壤溶液对玉米种子萌发和幼苗生长的影响。结果表明,种子发芽率、发芽指数和胚乳养分的利用率有所减少,但与焚烧前差异不显著;种子发芽势、活力指数和α-淀粉酶活性明显下降。幼苗芽长、苗鲜重和蛋白质合成减少不明显;幼苗主胚根长度、胚根数、叶绿素含量、净光合速率及干物质积累则明显减少。表明麦秆焚烧后的土壤溶液不利于玉米种子萌发和幼苗生长。     

不同花生品种种子形状与吸水速率的研究

以不同花生品种的种子为试材,采用水培方法研究了吸水速率与种子重量、长度、宽度、厚度间的关系。结果表明:不同品种花生种子吸水速率间存在明显差异,花育22号种子吸水速率最大,花育33号次之,花育20号种子吸水速率最慢。种子重量、长度、宽度、厚度四者间均表现显著正相关,即重量增加,其相应的长度、宽度、厚度均会增加。回归分析表明,不同花生品种种子重量随长度、宽度、厚度变化的回归模型存在差异;通过主成分分析得到载荷矩阵、比较载荷矩阵各形状指标的载荷值,结合灰色关联度分析,花育20号吸水速率与种子宽/重比的关联度最大、且两者为正相关,即相同重量下,花育20号种子子叶越宽,吸水速率越大,最大吸水速率为1.43mg/min。花育33号和花育22号种子吸水速率与种子长/重比的关联度最大,且为正相关,即相同重量下,花育33号和花育22号种子越长,其吸水速率越大,最大吸水速率分别为1.61mg/min和3.49mg/min。     

低温对花生种子发芽及幼苗生长的影响

在室内培养条件下,以青花7号花生品种为试验材料,系统研究了收获后低温对种子发芽及幼苗生长的影响。结果表明,随着处理温度的降低,种子的发芽势、发芽率、发芽指数和活力指数降低,幼苗主根长度、侧根长度和侧根数量减少,根系活力降低,出苗率降低。处理温度达到-1℃即对种子发芽和幼苗生长造成明显不良影响,可作为花生种子收获后受低温危害的阈值。     

种衣剂处理对低温胁迫下花生种子萌发及幼苗生长和生理特性的影响

花生播种期易受低温胁迫,为明确种衣剂处理对低温胁迫下花生种子萌发、幼苗生长和生理特性的影响,以常温(25℃)处理为对照(CK),设8℃和10℃两个低温胁迫处理,各温度下设种衣剂包衣和清水浸润对照两种处理方式,研究种衣剂处理对低温胁迫下花生种子活力、幼苗干物质积累、根系形态特征和光合生理的影响。结果表明,相对于常温处理,8℃低温胁迫处理显著降低了花生种子发芽势(5.9%)、发芽率(7.7%)、发芽指数(11.0%)、种子活力指数(6.9%)和幼苗叶片SPAD值(11.4%),同时对幼苗根系生长产生抑制作用,其根长、根表面积和根体积较25℃常温和10℃低温胁迫处理分别显著降低50.0%～50.2%、44.9%～48.1%、48.2%～48.5%,但8℃低温胁迫处理对花生幼苗地上部和地下部干物质积累、最大光化学效率及胞间二氧化碳浓度、气孔导度、净光合速率和蒸腾速率等光合参数均无显著影响;种衣剂处理显著提高了8℃低温胁迫下花生种子的发芽势(8.2%)、活力指数(10.9%)和花生幼苗根长(45.1%)及根表面积(38.4%),但对10℃低温胁迫和常温处理均无显著影响,同时,种衣剂处理还显著提高...     

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。     

产ALA光合细菌对陈化大豆种子幼苗建成若干指标的影响

为了降低ALA的生产和应用成本,在实验室条件下评估了产ALA光合细菌的培养物与低浓度商品ALA的溶液对陈化1年的大豆种子出苗和幼苗建成的若干生物学指标的影响。结果表明:供试产ALA光合细菌的培养液的上清液(ALA含量约为0.1~0.2 mg·L~(-1))、菌体悬浮液处理对陈化大豆种子萌发后幼苗株高和根系生长有显著促进作用,但对陈大豆种子的出苗率和幼苗下胚轴粗、鲜重、干重没有显著促进作用,而5 mg·L~(-1)的ALA溶液可显著提高陈大豆种子的出苗率、下胚轴粗、幼苗鲜重,1 mg·L~(-1)ALA可显著提高幼苗株高、下胚轴粗和干重。光合细菌的分泌物和胞外代谢产物对陈大豆种子萌发后幼苗的株高和根系生长有明显的促进作用。     

14株芽胞杆菌菌株的分子鉴定及其促生机理分析

以前期筛选的14株植物促生细菌为实验材料,运用16S rRNA基因序列同源性对菌株进行分子鉴定,通过生物测定评价菌株对番茄的促生效果,并对其促生机理进行初步分析。实验结果表明,促生菌株来自芽胞杆菌科的2个属、9个种。对番茄种子促生特性研究表明,14株芽胞杆菌均能提高种子发芽率,增长率为0.74%~11.85%;其中12株芽胞杆菌能促进胚根生长,增长率为4.03%~65.33%;而8株芽胞杆菌促进胚芽生长,增长率为1.24%~18.17%。对不同芽胞杆菌的促生因子相关分析结果表明,芽胞杆菌的6个促生因子（解无机磷、解有机磷、固氮效能、吲哚-3-乙酸含量、植酸酶活性、吡咯喹啉醌浓度）之间无相关关系（P>0.05）,与活菌数无相关关系（P>0.05）,与种子发芽率、胚根长、胚芽长也无显著相关关系（P>0.05）。种子发芽率与胚根长、胚芽长无相关关系（P>0.05）,而胚根和胚芽长之间具有显著性相关（P<0.01）。室内番茄盆栽实验表明,试验的6株芽胞杆菌对番茄幼苗均有促生作用,不同芽胞杆菌对番茄促生特性存在差异,如图瓦永芽胞杆菌FJAT-47648能显著增加根长,提升地上部与地下部干重,而暹罗芽胞杆菌FJAT-47226的促生效果则主要表现在增加株高和地上部生物量上。     

橄榄种子休眠生理与层积效应

探究橄榄种子休眠生理与层积对种子萌发和幼苗生长的影响效应,为橄榄及其他核果类果树种子休眠生理研究和种苗繁育提供参考。以未层积种子（层积0 d）为对照,对橄榄种子进行不同时间（每10 d一处理,共10个处理）的层积处理,研究橄榄种子在层积过程中营养物质、激素水平等生理生化变化,以及不同层积时间种子的萌发和幼苗生长情况。结果表明：层积处理缩短了橄榄种子发芽启动时间,对橄榄种子萌发均有促进作用。层积90 d和100 d的橄榄种子发芽率最高,均为82.22%,比CK种子（53.33%）高54.17%,发芽指数也显著高于其他处理时间,层积100 d的橄榄种子发芽指数是CK的8.5倍（P<0.05）。层积能提高橄榄幼苗地上部生物量,以90、100 d处理的橄榄幼苗生长最好。橄榄种子的主要营养贮藏物质是粗脂肪（70.85%~81.67%）,在层积过程中呈先升后降的趋势。新鲜橄榄种子（CK）中ABA含量较高（16.64 ng/g）,而GA₃未检测到。随层积时间延长,ABA与SA含量快速下降,GA₃含量增加,IAA/ABA升高,利于种子休眠解除。层积处理橄榄种子有利于其营养物质达到萌发所需水平,加快内源激素变化,促进种子发芽和幼苗地上部生长,以层积90~100 d最佳。     

Some effect fluid-sowing, pre-germination, irrigation and soil covering on the establishment and growth of seedlings of white clover slot-seeded into permanent pasture

Seeds of white clover ( Trifolium repens ) were sown alone or in fluid, or pre-germinated in fluid on to the soil surface of slots cut in an old Agrostis/Festuca sward. Seeds were left uncovered or covered with a thin layer of soil and irrigated from the outset or after 14 days delay.
With irrigation from the outset, seedlings established soonest from pre-germinated seeds but final percentage establishment ranged only from 50 to 63% for the three states of seed. With delayed Irrigation, however, few pre-germinated s1 survived and although germination of dry seed was delayed, final percentage establishment was unaffected. Soil covering increased establishment slightly. The number of leaves per seedling was greatest with pre-germination and early irrigation and least with pre-germination and delayed irrigation. Delayed irrigation also decreased the number of leaves per seedling for seedlings grown from dry seed.
The effects of early irrigation persisted so that at 84 days it significantly increased total yield of clover from all three states of seed, on average threefold, but much more from pre-germinated than from dry seed. Soil covering greatly increased yield, especially where irrigation had been applied from the outset. The interaction of early irrigation and soil covering was even more pronounced for stolon weights, and stolon growth of Individual seedlings appeared to benefit more from soil covering than from early irrigation.
The results showed the importance of early seedling emergence, but no advantages of fluid sowing per se. They also indicated large overall beneficial effects of early irrigation and its additive interaction with soil covering.     

Morphological and physiological traits of seeds and seedlings in two rice cultivars with contrasting early vigor

Early vigor is important for crop establishment in rice. This study was conducted to determine the seed and seedling traits in relation to early vigor in rice. Laboratory tests and pot experiments were carried out in 2013 and 2014. Morphological and physiological traits of seeds and seedlings were compared between two contrasting rice cultivars, Yuxiangyouzhan with superior early vigor and Huanghuazhan with general early vigor. For seed traits, Yuxiangyouzhan had lower seed hull weight but higher seed amylose content, seed amylase activity, and plumule–radicle ratio than Huanghuazhan, and consequently, Yuxiangyouzhan had about 10% higher germination percentage and velocity and 37% longer plumule than Huanghuazhan. For seedling traits, leaf area, specific leaf weight, leaf chlorophyll and soluble protein contents, leaf net photosynthetic rate, and shoot–root ratio were higher in Yuxiangyouzhan than in Huanghuazhan, and as a result, seedling shoot biomass was 23–32% higher in Yuxiangyouzhan than in Huanghuazhan. These results indicate that Yuxiangyouzhan has both superior seed and seedling vigor. The former is attributed to the low mechanical strength of seed hull, high conversion efficiency of seed reserve, and high mobilization of seed reserve to plumule, while the latter is due to large leaf area, high leaf photosynthetic capacity, and high partitioning of dry matter to shoot. This study enriches the physiological understanding of superior early vigor in rice.     

Seed longevity and seedling emergence rate of Urochloa decumbens as influenced by sowing depth in a Cerrado soil

Urochloa decumbens (Signal grass) is an African grass species that is widely used in Brazil for pasture formation, and it has a high potential for invading natural areas. This study evaluated the longevity of U. decumbens seeds in the soil seed bank and the emergence rates of seedlings from different depths. In the greenhouse (natural light; ~25°C), seeds were sown at depths of 0, 1, 2 or 3 cm, in trays filled with sterile soil, to assess seedling emergence. Seeds sowed on the soil surface began to germinate 3 days after sowing. Seeds sowed at depths of 2 and 3 cm germinated 5 days after sowing. No seedlings emerged after 15 days. The seedling emergence rate was 74 ± 7% with no significant difference between sowing depths. In the field, seed longevity was evaluated by burying 60 replicates of 100 seeds at a soil depth of 2–3 cm, in a Cerrado area in the IBGE Ecological Reserve, Brasília. From September 2016 to April 2017, five samples were retrieved monthly to assess seed viability. In September, the viability was 68%, declining to 3% in October; by February, viable seeds were no longer recorded. As U. decumbens flowers in several episodes throughout the year, a soil survey may result in a misleading interpretation of the formation of a permanent soil seed bank.     

红小豆、大豆以及菜豆的形态特征和出苗日数的相关性

对红小豆、大豆以及菜豆3种豆类品种的种子形态特性进行了调查。3种豆类品种种子的粒重和粒长、粒宽以及粒厚之间有很高的正相关关系。把各种豆类的粒长、粒宽以及粒厚之间的关系用直线回归系数来表示,并使粒形的形态特征数值化。另外,大豆和菜豆种子的粒重和种子所占子叶比率之间成正相关关系,种子的粒重和种子所占胚芽比率之间成负相关关系,但红小豆没有相关关系。通过两年试验,从播种到出苗日数,3种豆类中红小豆最晚（15～20d）。在降雨量多的年份红小豆的出苗日数和种子的大小没有相关性,但是大豆和菜豆的粒重和出苗日数之间成负相关关系。播种时期土壤水分充足时,大豆和菜豆粒重轻的种子比粒重重的种子先出苗,但是红小豆没有看到这种关系。这可能与种子的吸水速度有关。     

杂交稻低播量精量播种育秧及机插取秧特性

【目的】明确杂交稻70 g以下低播量精量穴播和条播对育秧效果及机插特性的影响,突破生产中杂交稻机插的技术瓶颈。【方法】以中浙优1号和甬优1540两个杂交稻品种为材料,利用机插标准9寸盘,设置机械穴播和条播两个精量播种方式,并以机械流水线撒播为对照,穴播规格为16(纵向)×34(横向)穴,条播为纵向16条,以穴播5粒、3粒及2粒的播种量进行播种试验。考查了低播量下不同播种方式对秧苗生长影响及配套取秧效果【结果】1)低播量下不同播种方式对秧苗成苗率的影响不大。2)降低播种量提高秧苗生长一致性,且穴播和条播秧苗生长一致性好于撒播。3)与撒播相比,精量穴播和条播能够在低播量下提高秧苗根系盘结力和成毯性,中浙优1号和甬优1540根系盘结力比撒播平均高75.4%和81.0%,播量每穴3粒时即能有效成毯,穴播和条播差异不大。4)精量穴播和条播能够显著降低低播量下机插漏秧率,中浙优1号和甬优1540机插漏秧率平均分别比撒播低76.3%和74.6%,穴播和条播下,两个品种每穴播量3粒的漏秧率均在1%以下,与撒播相比降幅在10个百分点以上。5)精量穴播和条播机插取秧苗数均匀度比撒播要好,两个品种预期取秧2~5苗(5粒)、1~3苗(3粒)和1~2苗(2粒)比例均达80%以上,中浙优1号和甬优1540机插苗数均匀度平均比撒播高121.2%和67.0%,其中,穴播机插取秧苗数均匀度及预期取秧苗数比例高于条播。【结论】精量穴播和条播可以解决目前杂交稻机插用种量大、漏秧率高和机插取秧苗数均匀度差的问题。     

Characteristics of Seedling Raising and Mechanized Transplanting of Hybrid Rice with a Low Seeding Rate by Precise Seeding Method

【Objective】 The purpose of the study is to ascertain the effect of precise hill-sowing and drill-sowing methods on seedling raising and the characteristics of mechanized transplanting of hybrid rice with a low seed sowing rate below 70 g, and to further break the current technical bottleneck in mechanized transplanting process of hybrid rice. 【Method】 In this study, Zhongzheyou 1 and Yongyou 1540 were mechanically hill-sowed and drill-sowed in standard seedling raising trays with mechanized broadcasting as the control. The hill-sowing specification was 16×34 hill, and 16 drills were set in longitudinal direction for drill sowing. The seed sowing rates were 5 seeds, 3 seeds, and 2 seeds per hill for hill sowing, and the same seed rates were set in drill sowing. The effects of different sowing methods on the growth of seedlings and their mechanical transplanting characteristics were investigated. 【Results】 1) Sowing methods presented no significant effect on seedling percentage with a reduction in seeding rate. 2) A reduction in seeding rate improved rice seedling consistency, especially in hill sowing and drill sowing as compared with broadcasting. 3) In comparison with seed broadcasting, under hill seeding and drill seeding, seedling roots were more entwined as seedling mats. Under hill-sowing and drill sowing, Zhongzheyou 1 and Yongyou 1540 had 75.4% and 81.0% higher intertwining force than that of broadcasting, respectively. Precise hill- and drill-sowing generated effective seedling blanket without significant difference between the two treatments, while broadcast sowing did not. 4) Hill sowing and drill sowing significantly reduced the missed hill percent of machine transplanting. The missed hill percent of Zhongzheyou 1 and Yongyou 1540 under hill sowing and drill sowing were 76.3% and 74.6% lower than that of broadcast sowing in average, respectively. The missed hill percent for hill-seeding and drill-seeding with 3 seeds per hill was below 1%, 10% lower than that of broadcast sowing. 5) The uniformity of machine-transplanted seedling under hill sowing and drill sowing were better than that of broadcast sowing. And the proportion of the treatments with expected seedling-catching number in mechanized transplanting (2 to 5 seedlings with 5 seeds per hill, 1 to 3 seedlings with 3 seeds per hill and 1 to 2 seedlings with 2 seeds per hill) for the two cultivars were all above 80% in hill-sowing and drill-sowing in combination with machine transplanting, and the seedling uniformity of machine-transplanted Zhongzheyou 1 and Yongyou 1540 was 121.2% and 67.0% higher than that under broadcast sowing. Meanwhile hill sowing had a better result than drill sowing. 【Conclusion】 Precision hill seeding and drill seeding provide an alternative measure to current problems such as large amount of seeds, high missed hill percent and uneven seedling taking in the process of machine transplanting of rice.     

盐胁迫对野生稻种子萌发及幼苗生长的影响

以3个野生稻品种(系)和常规稻品种吉粳301(CK)为试验材料,研究了不同NaCl浓度对野生稻种子萌发及幼苗生长的影响。结果表明,盐胁迫对野生稻和常规粳稻种子萌发及幼苗生长的影响不同,NaCl浓度≤0.3%时,盐胁迫对3个野生稻种子发芽及幼苗生长没有影响,但促进吉粳301种子发芽及幼苗生长;NaCl浓度≥0.5%时,随着NaCl浓度的增大,3个野生稻种子发芽率逐渐降低,幼苗的根长、苗长、根冠比逐渐变小;NaCl浓度与3个野生稻种子发芽率有一定的负相关性;NaCl对野生稻幼苗根的抑制作用强于对苗的作用;不同野生稻品种对NaCl溶液的耐受能力不同,从大到小依次为MY-3、延引红、HY-1。     

秸秆焚烧土壤提取液对大豆种子萌发和幼苗生长的影响

采用砂培法研究了秸秆焚烧土壤提取液对大豆种子萌发和幼苗生长的影响.结果表明,秸秆焚烧的土壤提取液可使大豆种子活力明显下降、根系发育受阻、脂肪酸含量减少、子叶储藏物质的转化率下降、幼苗生长受阻、干物质积累减少.