不同播种深度对玉米出苗的影响

采用盆栽试验,研究四川省丘陵区8个玉米品种在7个不同播种深度处理下的出苗率、出苗时间、幼苗形态特征以及干物质积累量的变化,探讨不同播种深度对玉米出苗的影响。结果表明,随播种深度增加玉米出苗率逐渐下降,出苗时间逐渐延后,其中,播种深度为3、6、9 cm处理平均出苗率分别为91.3%、89.4%和62.1%,在此范围内苗长和中胚轴长逐渐增加,主根长和幼苗整齐度逐渐减小,苗干重和中胚轴干重逐渐增加,根冠比逐渐减小,根干重差异不显著,与玉米出苗率关联度最大的是中胚轴长和中胚轴干重。不同玉米品种对播深的忍耐能力存在一定差异,中单808、成单30和川单418的耐深播能力较强。     

玉米种子大小和播深对出苗和幼苗活力的影响

林波波河省小农户主要以玉米为主粮来生产,播种时常因翻耕翻埋种子而造成植株个体生长差。本研究目的就是要确定种子大小和播种深度对玉米出苗和生长的影响。实验处理包括两种不同大小的种子（大粒种子和小粒种子）和4个播种深度（5cm、10cm、15cm、20cm）。种子大小对出苗率无显著影响,但不同播深对出苗率有显著影响。种子大小和播种深度均对幼苗高度有显著影响。种子大小对幼苗干重和叶片数没有影响。随播种深度增加,幼苗干重减少。结果显示,播深在5cm和10cm时,种子大小对出苗和幼苗活力没有影响,但播种深度在15cm和20cm时,对出苗和种子活力有不良影响。     

滇重楼播种技术研究

大田条件下播种的滇重楼种子出苗率低、出苗时间长和出苗不整齐,是滇重楼生产的瓶颈。本研究比较了直接播种、催芽播种、播种基质、播种深度、土壤水分等播种技术对滇重楼出苗率、出苗整齐度的影响。直接播种：以0.8 cm2≤S(种子投影面积)＜1 cm2出苗率最高,依次为S≥1 cm2,0.65 cm2≤S＜0.8 cm2,0.5 cm2≤S＜0.65 cm2,S＜0.5 cm2的种子不出苗;播种基质为土-沙组合出苗时间较腐叶土基质提前13个月,播后18个月出苗率搞出了26.33 %。催芽播种胚根长度越长其出苗率相对     

中国玉米主产区栽培品种种子质量分析

以黄淮海、华北、西南三区46个玉米栽培品种种子为材料,通过物理化学指标测定、标准发芽及幼苗生长测定、逆境发芽测定、田间出苗率测定、指标间相关性分析、淀粉酶活力测定等对种子质量进行分析评鉴。结果表明,46个品种中马齿型和半马齿型的比例占80.4%。综合各项种子活力指标,排名前4位的高活力品种为先玉047、郑单958、大华玉2号和浚单26。玉米种子容重和总淀粉含量与平均田间出苗率分别呈极显著和显著正相关;发芽势、发芽率及逆境发芽各指标与平均田间出苗率均呈极显著正相关,其中抗冷测定发芽率的相关系数最高(r=0.881)。玉米种子容重和总淀粉含量是高活力玉米种子具备的典型性状,抗冷测定为玉米种子活力检测的最适方法;高活力玉米品种种子萌发中同一时期淀粉酶活力明显高于低活力玉米品种种子。     

云南省地方玉米种质资源的类型、品种及其子粒颜色多样性分析

对云南省地方玉米种质资源类型、品种(遗传)及子粒颜色的整理和分析,表明云南省玉米地方种质资源共有7个类型.类型多样,分布广泛,但不同类型的生态分布区和品种及其子粒色泽多样性存在较大差异.硬粒型品种及其子粒色泽多样性指数最大,品种数最多,占地方种质总数的58.2%;其次是半马齿型和糯质型品种,子粒颜色以黄、白色为主,分别占品种总数的43.3%和42.8%,其他颜色较少.糯质型品种主要集中分布于滇南和滇中两大生态区,存在不同的品种类型和丰富的种质资源,以及水平分布的区域性和立体分布的生态特点.硬粒型玉米品种的多样性与云南省的耕地成分、分布状况、人们种植和利用玉米的目的及用途密切相关.糯质玉米的丰富性、多样性和生态分布特点主要与云南省各民族人民的民族饮食文化密切相关。     

小麦种质资源耐深播性评价体系研究

为建立准确、简单易行的种质资源耐深播评价体系,以15份耐深播能力存在不同程度差异的小麦种质为材料,在大田环境下,研究6个播种深度(5 cm、7 cm、9 cm、11 cm、13 cm、15 cm)下小麦出苗率、出苗时间、苗高、地中茎长、胚芽鞘长、胚芽鞘横截面积及初生根长的差异,筛选小麦耐深播评价的最佳播种深度及其密切相...     

播种深度对滨海稻区水稻旱直播生育及产量的影响

为探明播种深度对滨海稻区水稻旱直播生育及产量的影响,以盐粳1403、盐粳927、盐粳933为材料,采用盆栽方式进行了水稻旱直播播种深度研究。结果表明,水稻旱直播播种深度在2 cm、3 cm效果最佳,两个处理间差异不大。播深2 cm较播深3 cm、4 cm、5 cm、6 cm三个品种平均出苗率分别高出1.29、21.05、41.15、49.06个百分点,出苗时间分别提早1、3、5、7 d,中胚轴长度分别短0.37、0.9、1.14、1.5 cm;各时期茎蘖数随播种深度增加逐渐减少,齐穗期推迟1～7 d,成熟期推迟1～9 d;三个品种平均实际产量播深2 cm最高,比播深3 cm、4 cm、5 cm、6 cm分别高0.48%、18.16%、41.47%、53.26%。     

硬粒小麦若干淀粉性状研究

为了解硬粒小麦品种不同磨粉样品和不同类型间的淀粉品质特性,测定了2个硬粒小麦品种4种不同磨粉样品的膨胀势和5个不同类型品种的膨胀势和直链淀粉含量。结果表明,2个硬粒小麦品种不同磨粉样品的膨胀势均以淀粉最高;缺失4A型和7A型的硬粒小麦品种具有膨胀势高、直链淀粉含量低的特性。文中还对我国硬粒小麦品质改良作了讨论。     

不同收获期玉米杂交种种子活力研究

选择硬粒型先玉335、马齿型郑单958和吉祥1号3个杂交种,研究河西制种基地玉米杂交种种子成熟度与种子活力的关系。研究结果表明,不同玉米杂交种授粉后不同采收期对种子活力影响影响很大,灌浆前期种子成熟度低,具有一定的发芽率,但种子抗逆能力差,低温冷害后的冷浸发芽率大幅度降低,田间出苗率更低;随着灌浆时期的延后,种子成熟度提高,抗逆能力逐渐增强,授粉后52 d采收3个品种冷浸发芽率达到标准发芽率的96.1%~97.6%,田间出苗率达到标准发芽率的80.4%~82.6%。授粉后57 d采收3个品种冷浸发芽率超过86%,达到标准发芽率的91%;田间出苗率达到最高(91%),是标准发芽率的95%。甘肃武威制种基地先玉335授粉后52 d以后(9月15日)收获,郑单958和吉祥1号授粉后57 d以后收获种子活力达到最高,比目前生产上收获期提前10~15 d,可有效避免早霜对玉米种子冻害的影响。     

夏玉米幼苗的生长发育对播种深度的适应性

在土质为中壤土的地块上观察了玉米单交种种子的发芽及幼苗生长发育对播种深度的适应性。结果表明,从出苗率、出苗期、幼苗高度及幼苗干重等指标综合考虑,认为播种深度6～12cm均可。播种深度浅于6cm,种子出苗率和幼苗的生长发育易受上层土壤的水分蒸发影响,深于12cm种子出苗率明显降低,因此认为在较为干旱又无灌溉的条件下,夏直播或套种玉米的播种深度可较常规深度增加,直至12cm。     

不同玉米品种及其亲本耐深播特性分析

以10份玉米杂交种及对应的19份父母本为材料,在播深5、10和15 cm条件下,对出苗率、苗长、根长、中胚轴长、芽鞘长、苗重、根重和中胚轴重等指标进行变异分析以及杂交种与其父母本出苗率的相关分析。在播深15 cm条件下,通过指标筛选出辽单588、辽单1211、辽单565和辽单575等4个玉米杂交种为耐深播品种;辽3313、辽6049、XL21、辽7980和辽2386为耐深播玉米自交系。在玉米杂交种和自交系中,中胚轴长和根长与田间出苗率均达到显著相关,说明中胚轴长和根长在玉米深播后对出苗起到关键性作用。     

THE EFFECT OF SEED WEIGHT AND DEPTH OF SOWING ON THE EMERGENCE AND EARLY SEEDLING GROWTH OF PERENNIAL RYEGRASS (LOLIUM PERENNE)

Seed of S24 perennial ryegrass of two weight ranges, 0.9–2.1 and 2.5–3.6 mg, were sown in soil at depths of 1.25, 2.5, 5.0 and 7.5 cm. Seedling growth was studied during the 3 weeks following germination.
Seeds of both weight ranges germinated equally well at soil depths down to 7.5 cm. However, the number of shoots that emerged was reduced as the sowing depth increased. At similar depths of sowing, seedlings from the heavy seed were heavier and developed more leaves and tillers than those from light seed. Deeper sowing reduced seedling weight and the rate of leaf- and tiller-production. After emergence, the relative growth rates of the seedlings which grew from seed of both weight ranges were similar at those depths of sowing which permitted the highest proportion of emerged shoots to seeds sown. This indicates that the weight advantage gained by the seedlings that developed from heavy seed during their non-photosynthetic stage of growth was maintained, and was not increased by a greater relative growth rate after photosynthesis began.
The implications of the findings are discussed in relation to plant breeding, commercial seed production and sward establishment.     

中国北方杂草稻深覆土条件下出苗动力源分析

 以盆栽的方式,采用不同的覆土深度,对中国北方杂草稻的出苗特性进行了研究,分析了杂草稻的出苗动力源。研究结果表明,在中国北方发现的部分杂草稻具有较强的中胚轴伸长特性和芽鞘节间伸长特性。在播种深度较浅时（3 cm）,杂草稻依赖于中胚轴的伸长顶土发芽;当覆土较深时（5 cm）,杂草稻中胚轴伸长特性更加明显,伸长长度加大,同时杂草稻的芽鞘节间也明显伸长,中胚轴和芽鞘节间的共同伸长为深覆土条件下杂草稻的出苗提供了动力基础。     

Ludwigia hyssopifolia emergence and growth as affected by light, burial depth and water management

Experiments were conducted to evaluate the effects of light, seed burial depth, and flooding on germination, emergence and growth of Ludwigia hyssopifolia. Germination was strongly stimulated by light, suggesting that seeds of this species are positively photoblastic. Seeds sown on the soil surface gave the greatest percentage of seedling emergence in plastic trays, and no seedlings emerged from seeds buried in soil at depths of ≥1 cm. Intermittent or shallow flooding suppressed emergence and growth of L. hyssopifolia. Flooding to a depth of 2 cm for 4 days out of 7 days reduced seedling emergence by more than 71% and seedling dry matter by 97% compared to where the soil had not been flooded. Flooding up to a depth of 10 cm however, when delayed to 21 days after sowing, did not significantly suppress growth of this species. This study illustrates the role of seed burial by tillage and flooding as two important tools for the management of L. hyssopifolia.     

播种深度对夏玉米冠层结构及光合特性的影响

选用郑单958(ZD958)和先玉335(XY335)为试验材料,设置3、5、7、9 cm 4个播深处理和4个播种深度混播的播深不一致处理(U),研究播种深度对夏玉米冠层结构、光合特性和产量的影响。结果表明,播深不一致显著降低株高、穗位高、果穗长度等性状整齐度,影响群体冠层结构,ZD958和XY335的产量较3、5 cm播深分别下降2.6%、3.2%和0.9%、3.9%。播种过深,整个生育期内的植株性状整齐度和叶面积指数较低,穗位高及底层透光率增加;SPAD值及比叶重较低,净光合速率和单株干物质积累下降。ZD958和XY335播深9 cm的产量较3、5 cm播深分别下降5.9%、6.4%和6.1%、8.8%。播深7和9 cm,夏玉米群体密度降低,冠层透光率增加,但其叶面积指数、SPAD值和比叶重降低,净光合速率和单株干物质积累下降,最终降低夏玉米产量。     

Factors Relating to Seedling Emergence in Spring Wheat

Abstract

Spring wheat (Triticum aestivum L.) is cultivated in the northern part of Japan. Although the vigorous early growth of spring wheat is desirable, the rapid and uniform emergence of seedlings is reduced by adverse environmental effects, such as excessive soil moisture and low temperature. Analyses of correlations between field emergence day and germination traits under low temperature, after treatment with polyethelene glycol (PEG) and after flooding treatment of 44 varieties from Japan and other countries indicated a general absence of interrelationships. Moreover, there was no significant correlation between field emergence days in trials in 1996 and 1997. Small and large seeds of Haruyutaka harvested in 1994 and 1996 were hand-sown at depths of 3 cm and 10 cm without fertilizer and with standard fertilizer in brown forest soil in a field of the Tokyo University of Agriculture in Hokkaido. The superiority of large seeds over small seeds was demonstrated by the production of more shoot dry matter with sowing at a depth of 3 cm and by the number of emerged plants with sowing at a depth of 10 cm. Although the coefficients of correlation between field emergence day and germination traits of the wheat varieties were low, a sowing method that optimized seedling growth in the field was demonstrated in this experiment.     

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.     

Establishment of rice determined by interaction between cultivar,sowing depth,and time between irrigation and sowing,in north west Australia

The influences of cultivar, depth of sowing, and time between pre-irrigation and sowing, on rice crop establishment were investigated by drilling into moist soil during the dry season in N.W. Australia.As the time between pre-irrigation and sowing increased, median seedling emergence was delayed, and spread of the population's emergence rate and final percentage emergence decreased, particularly for shallow sowing depths. Delayed sowing also resulted in less-vigorous growth of some seedlings. Stomatal conductance was generally lowest in seedlings emerged from shallow depths although leaf-air temperature differentials and measurements of stomatal conductance, usually regarded as reliable indices of plant water status, failed to distinguish between cultivars or sowing treatments.Delaying sowing, with attendant cultivation, for more than 10 days after pre-irrigation resulted in negligible weed populations. The tall, vigorous-growing cultivar Pelde (ex N.S.W.), sown at 6–8 cm depth between 10 and 15 days after pre-irrigation reached sufficient height for permanent flooding within 50 days after sowing. A semi-dwarf cultivar IR661-1-170-1-3 (ex IRRI) proved more sensitive to depth and time of sowing following irrigation; because of its slower growth rate and additional irrigation requirements it was less adapted to this method of establishment.     

黑土不同耕层厚度对玉米根系形态空间分布及其产量的影响

在重建不同厚度黑土层的定位模拟试验区开展免耕玉米大豆轮作试验,设3个黑土耕层厚度(10、20和30 cm),探究不同耕层厚度对玉米生育期间的根系形态及其产量影响。研究表明,玉米产量对不同耕层厚度反应敏感,30 cm耕层厚度处理玉米产量最高,比20 cm和10 cm耕层厚度显著高12.5%和24.1%,且玉米根系分布对耕层厚度响应差异明显。30 cm耕层厚度显著影响玉米0～10 cm土层根重密度,对10～30 cm土层根重密度及不同土层根长密度和比根长影响不明显。