不同播种深度对羊草出苗率和幼苗生长的影响

利用盆栽研究了7种播种深度(0cm、1cm、2cm、3cm、4cm、5cm和6cm)对羊草出苗率和幼苗生长的影响。结果表明,羊草出苗率与种子萌发率呈极显著正相关(r=0.9147),而与播深呈极显著负相关(r=-0.9408)。在浅播(0～2cm)条件下,羊草初始出苗时间为5.0～7.7d,最终出苗率为70.0%～80.7%;在深播(4～5cm)条件下,初始出苗时间延迟到16.3～20.0d,羊草种子萌发率下降到41.0%～43.0%,但出苗率不足7%,株高不超过2cm;当播深在6cm以上时,其萌发率为37.0%,但出苗率为0。此外,播种深度显著影响羊草幼苗株高、茎叶鲜重及叶片数量。     

收获期对“阿坝”硬秆仲彬草种子质量的影响

在红原县二龙场牧草试验基地开展了不同收获时间对"阿坝"硬秆仲彬草种子质量的影响试验。结果表明:随着收获时间的推迟,"阿坝"硬秆仲彬草种子含水量显著下降(P<0.05),千粒重、发芽率、田间出苗率和加速老化后的发芽率在8月25日之前显著增加(P<0.05),结实率在8月20日之前显著增加(P<0.05)。综合种子质量的各项指标,结合红原地区的高寒气候条件,建议"阿坝"硬秆仲彬草种子在该地区及类似地区的收获时期不早于9月5日。     

"阿坝"硬秆仲彬草品种选育报告

以川西北高寒牧区沙化草地上生长的野生硬秆仲彬草为材料开展新品种选育,采用改良混合选择法,育成抗旱能力强、种子产量高的HY02-4硬秆仲彬草新品系,经品种比较试验、区域试验、生产试验表现良好,命名为"阿坝"硬秆仲彬草.     

“阿坝”硬秆仲彬草品种选育报告

以川西北高寒牧区沙化草地上生长的野生硬秆仲彬草为材料开展新品种选育,采用改良混合选择法,育成抗旱能力强、种子产量高的HY02-4硬秆仲彬草新品系,经品种比较试验、区域试验、生产试验表现良好,命名为"阿坝"硬秆仲彬草。     

"阿坝"硬秆仲彬草苗期对2,4-D丁酯和阔极的耐药性研究

为确定2，4 D丁酯、阔极（苯·唑·2甲钠）在防除“阿坝”硬秆仲彬草(Kengyilia rigidula cv.Aba)苗期杂草时的安全施用剂量，进行了苗期耐药性试验。结果表明，2，4 D丁酯施用剂量为7502 250 mL/hm2、阔极施用剂量为300900 g/hm2时，对阿坝硬秆仲彬草茎叶形态没有任何的影响。2，4 D 丁酯施用剂量为7503 000 mL/hm2，阔极施用剂量为3001 200 g/hm2时，对“阿坝”硬秆仲彬草的存活率、植株高度、分蘖能力无明显影响。当2，4 D丁酯施用剂量超过3 000 mL/hm2，阔极剂量超过1 200 g/hm2，硬秆仲彬草地上地下生物量显著低于对照（P<0.05），硬秆仲彬草表现出一定的药害反应。研究认为，2，4 D丁酯防除“阿坝”硬秆仲彬草苗期杂草最大安全剂量为3 000 mL/hm2，阔极最大安全剂量为1 200 g/hm2。     

硬秆仲彬草种子生产技术

根据试验研究和生产实践,总结提出了硬秆仲彬草种子生产技术规程,对种子生产的地点选择、种子繁殖田建植、管理以及种子收获等生产环节提出了具体的技术要求和实施办法。     

荒漠草原人工柠条对冠下蒙古冰草种子萌发和幼苗生长的影响

本研究以盐池县荒漠草原人工柠条林（Caragana intermedia）为研究对象,将蒙古冰草（Agropyron mongolicum）种子分别播于柠条冠下两侧（东侧SE,西侧SW）及带间（CK）,通过定期观测微气候及蒙古冰草的种子萌发和幼苗生长,探讨人工柠条林对冠下微气候、蒙古冰草种子萌发和幼苗生长的影响。结果表明：SW和SE的土壤温度分别为18.57℃和18.51℃,显著低于CK（P<0.05）,空气相对湿度分别为40.73%和34.51%,高于CK;不同微生境条件下蒙古冰草幼苗数均在播种后60 d达到最高,自出苗开始至结束,SW和SE的幼苗数均显著高于CK（P<0.05）,总出苗率分别较CK增加了18.97%和20.00%,存活率分别较CK增加了24.04%和17.34%;自播种后45 d起SW和SE的苗高均显著高于CK（P<0.05）,至90 d时SW和SE的苗高分别达10.19 cm和10.01 cm;冗余分析表明空气相对湿度和土壤有机碳是影响蒙古冰草种子萌发和幼苗生长的主要因子。综上所述,柠条灌丛对蒙古冰草种子萌发和幼苗生长具有一定的保育作用。     

硬秆仲彬草种子生产技术

根据试验研究和生产实践，总结提出了硬秆仲彬草种子生产技术规程，对种子生产的地点选择、种子繁殖田建植、管理以及种子收获等生产环节提出了具体的技术要求和实施办法。     

电场处理冰草种子对其幼苗生长的影响

用不同强度的匀强电场作用冰草种子,实验测定电场对出苗率及幼苗生长的影响,对测试结果利用数学方法进行统计推断。结果表明：不同电场对冰草种子萌发及幼苗生长产生不同的影响,用1.0kv/cm电场强度处理冰草种子10min,可提高种子出苗率4.5%,苗长增长81%,根长增长48%;用4.5kv/cm电场强度处理冰草种子10min,可提高种子出苗率4.8%,苗长增长84%,根长增长66%。     

“阿坝”硬秆仲彬草适宜播种期试验研究

2012～2013年在四川省红原县开展了“阿坝”硬秆仲彬草适宜播种期试验,试验结果表明,不同播种期对“阿坝”硬秆仲彬草生长发育影响较大.在川西北高寒牧区,4月15日至6月30日为“阿坝”硬秆仲彬草的适宜播种时间.     

沙生针茅种子发芽试验

采用不同方法处理沙生针茅(Stipa glareosa)种子,测定沙生针茅种子发芽率和种子出苗率,以探明影响沙生针茅种子萌发和播种出苗的制约因素。结果表明:60℃蒸馏水浸泡种子24 h,种子吸水率、发芽率、发芽势分别为26.3%,38.0%和32.0%;-20℃、20℃低温变温处理96 h,发芽率和发芽势分别为46%和48%;用80 mg/L GA_3水溶液浸泡种子24 h,发芽率和发芽势分别为54%和48%;沙埋深度会影响沙生针茅种子发芽和出苗,沙埋0.5 cm沙生针茅的种子发芽率和幼苗出土率最高;埋深超过2cm的深度,发芽率和出苗率降低;埋深6~8 cm,随着沙埋深度增加,出苗率显著减少;当埋深8 cm的深度,沙生针茅出苗率为0。     

埋藏深度对醉马草种子萌发与幼苗生长的影响

通过室内控制试验探究醉马草种子萌发及幼苗生长对不同埋藏深度的响应,结果表明:醉马草出苗速率随着埋藏深度增加呈先增后降趋势,1cm和2cm埋藏深度时出苗速率最大,同时发芽势(86.67%、72.22%)和萌发指数(1.83、1.66)均显著高于其他埋藏深度(P<0.05);醉马草种子在0~8cm埋藏深度范围内萌发率均在66.67%以上,但是出苗率在1cm和2cm埋藏深度时最高,分别为90%和88.78%,当埋藏深度≥4cm时会抑制出苗,埋藏深度9cm时不再萌发;随着埋藏深度的增加,醉马草茎长、幼根长和幼苗总长都呈先增加后下降的趋势,总茎长在4cm埋藏深度时最长(116.71cm),幼苗总长在2cm埋藏深度时最长(192.23mm),幼根长度在1cm埋藏深度时最长(97.37mm),而根茎比则随着埋藏深度的增加逐渐降低。总之,醉马草种子萌发出苗最适埋藏深度为1~2cm,当埋藏深度为9cm时种子不再萌发。     

Response of Seed Germination and Seedling Growth to Sand Burial of Two Dominant Perennial Grasses in Mu-Us Sandy Grassland,Semiarid China

Sand burial is an important selective pressure for growth, survival, and distribution of sand dune plants. Its effects on seed germination and seedling establishment, however, for different species are quite different. Experiments were conducted in the Mu-Us Sandy Grassland of North China to determine the effects of sand burial on seed germination and seedling growth of dominant perennial grasses Psammochloa villosa (Trin.) Bor and Leymus secalinus (Georgi) Tzvel. Small, medium, and large seeds of P. villosa and small and large seeds of L. secalinus were buried at 0-, 1-, 2-, 4-, 6-, and 8-cm depths in sand. P. villosa seed germination and seed dormancy in sand were significantly influenced by sand burial depth but not by seed size, whereas seed germination and seed dormancy of L. secalinus were significantly influenced by both sand burial depth and seed size. Emergence percentages for large seeds were higher than those for smaller seeds, suggesting that larger seeds are ecologically better adapted to dune habitats. Seeds that did not germinate in sand were in enforced dormancy and formed a soil seedbank, which can enhance plant survival on sand dunes. One-week-old and 2-wk-old P. villosa seedlings could tolerate 75% and 100% of their shoot height of sand burial, respectively, and the shoot elongation growth was enhanced by the burial stress. Both 1-wk-old and 2-wk-old seedlings of L. secalinus only tolerated up to 75% sand burial. The growth of L. secalinus seedling was inhibited by sand burial due to the decreased biomass and slow shoot elongation. The lack of tolerance of seedlings of this species to total sand burial might restrict its distribution on sand dunes.     

三种一年生藜科沙生植物出苗对沙埋深度和水分条件的响应

通过盆栽控制试验,研究了沙米、大果虫实和长穗虫实3种一年生沙生植物在4个模拟降水水平(A、B、C和D)和6种埋深水平(0,10,20,30,40和50 mm)的出苗情况。结果表明,3种植物种子均没有休眠现象。沙米和长穗虫实均在10 mm埋深处的出苗率最大,而大果虫实在30 mm埋深处的出苗率最大,沙米、大果虫实和长穗虫实,各降水处理的平均出苗率分别为50.63％,77.29％和75.21％。在沙土表面的种子,沙米萌发受强烈抑制,而其余2种植物在降水较多的A、B和D处理下萌发较多但成苗较少。这3种植物耐埋深的大小依次为:大果虫实>沙米>长穗虫实。降水量越大,其出苗率越高,沙米和大果虫实单次强降水下其种子出苗率大于等量的多次少量降水的积累,但是长穗虫实相反。这表明在干旱半干旱沙地,降水是调节季节性种子出苗最重要的决定因素,种子在沙土中的垂直分布决定了降水后种子萌发的比例并有助于维持土壤种子库。     

家系、种子产生部位和土层深度对黄帚橐吾种子萌发出苗的影响

黄帚橐吾(Ligularia virgaurea)是青藏高原高寒草甸一种典型的毒杂草。本研究主要分析了无光照条件下温度对黄帚橐吾种子萌发的影响,家系、种子产生部位和土层深度对黄帚橐吾种子出苗的影响。结果表明:温度对黄帚橐吾种子萌发率有显著的影响,随着温度升高萌发率下降,变温18/28℃下黄帚橐吾种子萌发率为87.33%,5/15℃下黄帚橐吾种子萌发率最高,达95.33%。土层深度对黄帚橐吾种子出苗率有显著的影响,土层越深,出苗率越低。土层深度为0 cm时,出苗率最高,达61.66%;土层深度为3 cm时,出苗率锐减;土层深度5 cm时,出苗率为0。家系和种子产生部位对黄帚橐吾种子大小、出苗率均有显著的影响。     

无芒隐子草种子萌发、出苗和幼苗生长对土壤水分的响应

研究了无芒隐子草种子萌发、出苗和幼苗生长对土壤含水量的响应。结果表明,在1%~20%土壤含水量条件下,沙质土壤中种子室内萌发和户外盆栽出苗的最适土壤含水量均为6%~8%。种子室内萌发率和萌发指数最高值分别为64.0%和16.6;户外盆栽的出苗率、成活率和出苗指数最高值分别为33.5%,29.5%和6.6。盆栽幼苗的最适生长土壤含水量为8%(幼苗生物量最大);在3%~20%土壤含水量间,随含水量增加植株将更多的能量用于地上部分生长。     

氮磷钾配施对甘草育苗质量的影响

利用“3414”方案进行N、P、K营养液配方设计,在配方营养液浇灌条件下进行甘草育苗质量比较,旨在探寻适宜甘草育苗的施肥配方,为其测土配方施肥和无土栽培育苗提供依据。结果表明,以纯沙石作为育苗基质,在添加Hoagland营养液条件下,不同N、P、K配比营养液对经98%硫酸处理的甘草种子的出苗质量和幼苗生长发育均具有极显著影响。N₂K₂配比下出苗质量均优于空白对照,且随着施磷水平的提高出苗质量呈下降趋势,出苗质量依次为N₂P₀K₂＞N₂P₁K₂＞N₂P₂K₂＞N₂P₃K₂。而出苗活力依次为N₂P₁K₂＞N₂P₀K₂＞N₂P₂K₂＞N₂P₃K₂。N₂P₂K₂和N₂P₁K₂处理均可极显著提高甘草根系活力,为培育壮苗奠定良好基础。单纯缺N、缺K和过量N、P和K肥均不利于甘草出苗和幼苗的生长发育。以上说明在甘草出苗阶段需P量小,但出苗后开始显示其营养效应。从育苗效益和环境保护双重考虑,配方施肥宜采用N₂P₁K₂,即添加80 mg/L NH₄NO₃、89 mg/L KH₂PO₄和298 mg/L KNO₃作为N、P和K营养源,每隔20 d浇1次。需要注意的是浇灌后应及时喷灌适量水,使氨态氮下渗到底部基质,以避免氨的挥发而灼伤幼苗。     

苦豆子种子形态特性及发芽条件研究

野生苦豆子种子硬实率高,因种皮不透水和不透气,而具有深休眠性。本研究观测了野生苦豆子种子的形态特征、种子大小、千粒重和硬实率,并对H₂SO₄破除种子硬实的处理浓度和时间,植物生长调节剂和聚乙二醇(PEG)处理对种子萌发和幼苗生长的影响,以及种子田间萌发的适宜土壤含水量和播种深度进行了研究。结果表明:苦豆子种子长为3.865mm,宽为3.358mm,厚为2.321mm,千粒重为20.775g,硬实率达99%;破除硬实处理适宜的H₂SO₄浓度为65%,时间是20min;0.02%GA3对提高种子发芽速度和幼苗生长量具有显著的作用,此外PEG处理种子能显著提高幼苗的生物量;苦豆子种子田间萌发的适宜土壤含水量为8%～12%,播种的最适深度是1～3cm。     

Germination Ecology of Cenchrus biflorus Roxb.: Effects of Environmental Factors on Seed Germination

Better understanding related to germination and seedling emergence of plant species assists in predicting the potential distribution and provides insight for efficient management. Cenchrus biflorus Roxb. has been considered as potential forage species in arid environment due to its high nutritive values, prolific seed production, and tolerance to extreme temperature and prolonged drought conditions. A series of laboratory and greenhouse assays were conducted to determine the effect of different environmental factors, such as temperature, light, pH, salinity, osmotic potential, and seed burial depth on the germination and seedling emergence of C. biflorus. The maximum germination (95%) was recorded at 35°C/25°C, followed by 40°C/30°C; however, minimum germination was observed at 45°C/35°C (17.5%). Light significantly promoted the germination with maximum percentage (97.5%) when seeds were exposed to altering light and dark conditions (12/12 h). The osmotic potential for the 50% inhibition of C. biflorus germination was –0.4 MPa, although some seed germinated at –0.8 MPa (12.5%). Germination decreased from 97.5% to 12.5% as salinity stress increased from 0 mM to 200 mM sodium chloride (NaCl) with no germination > 200 mM. Seed germination was significantly affected by pH levels and was between 27.5% and 92.5% at 5–8 pH, respectively. No seedling emerged when seeds were placed on the soil surface; maximum seedling emergence (90%) at 2-cm burial depth and emergence decreased considerably as seeding depth increased above 2 cm. Its tolerance to drought and salinity make C. biflorus a potential candidate to be used as an alternative source during periods of forage scarcity under harsh climatic conditions, and it could possibly be used for rangeland rehabilitation purposes in arid environments.