Effect of seed coat on peach seed germination

Various treatments to remove the seed coat surgically revealed its role in preventing germination of non-stratified peach seed. The peach embryo from a non-chilled seed is not dormant, as it germinates readily when the seed coat is completely removed. The peach seed coat provides a physical impediment — commonly referred to as mechanical resistance to germination. Incision through the seed coat around the seed at the cotyledonary gap allowed germination even though the seed coat remained in contact with the embryo. No role for inhibitors extracted from the seed coat could be elucidated.     

影响野生杏种子萌发的相关因素研究初报

试验以新疆野生杏的单株种子为材料,通过低温层积、机械去壳、去种皮及赤霉素处理等方法,研究不同处理对野生杏种子休眠及萌发的影响.结果表明:野生杏种子经过低温层积处理后,在一定时间内,随着层积时间的延长,发芽率也随之提高;低温层积处理40 d后野生杏种子开始萌发,100 d后发芽率可达90%;野生杏种子的种壳和种皮不同程度的抑制了种子萌发,去除种壳可使种子萌发提前,同时提高其发芽率;未层积的种子在去除种皮后用清水处理24 h,在25℃条件下,种子的萌发率达到80%以上,说明去除种皮能基本解除种子的休眠;一定浓度的GA3对野生杏种子的萌发具有促进作用.6号带壳种子与去壳种子的最适GA3浓度均为100mg/L,发芽率分别为86.7%、100%.而7号带壳种子的最适GA3浓度为300 mg/L,发芽率为70%.     

Pollinizer influence on almond seed dormancy

Breaking seed dormancy is necessary for the completion of germination. Maternal tissues (integument and endocarp) appear to control seed germination, although the effect of the pollinizer has also been described. In this work, the influence of the pollinizer flowering time was studied on the stratification requirements of almond seed germination. Stratification requirements were determined in seeds (with and without endocarp) from crosses between a female progenitor and pollinizers of different flowering dates. The results showed an influence of the pollinizer in the stratification requirements of seeds with endocarp. However, no correlations were found between pollinizer flowering date and stratification requirements, which seem to be determined mainly by the female progenitor. In the case of seed stratification without endocarp, the results did not show any influence of pollinizer on stratification requirements. The observed variability within females (within or between crosses) could be due to differences in the shell characteristics, the different accumulation of inhibitors in the integument, or the genetic nature of the embryos.     

桃果实缝合线软化过程中内源激素的变化

为了明确桃果实缝合线过早软化的原因,以大久保桃为试材,利用气质联用和高效液相色谱的方法,对缝合线软化果(障碍果)和正常果的种仁、缝合线处果肉和其它部位果肉中的生长素(IAA)、玉米素(Z)、脱落酸(ABA)、茉莉酸(JA)的浓度进行了测定分析。结果表明,果肉ABA浓度是种仁的8～9倍,并随着果实的发育逐渐增加,接近成熟时达到最高,主要表现出对果肉成熟的调控作用。障碍果中Z的浓度在内果皮硬化初期明显高于正常果,与其缝合线异常生长(凸起)吻合;障碍果种仁的IAA浓度在内果皮硬化初期明显低于正常果,果肉中IAA浓度在内果皮硬化后上升,且障碍果高于正常果,说明IAA对中果皮细胞的扩大与成熟软化起调控作用。JA在种仁中的浓度是果肉的3～6倍,在硬核初期障碍果明显低于正常果,到硬核结束时则高于正常果,推测可能JA与内果皮发育有关。     

不同处理对果梅种子萌发的影响

以优选果梅‘黔荔1号’种子为材料,研究赤霉素、低温层积和破壳处理对果梅种子萌发的影响.结果表明:以浓度为50 mg/L的赤霉素溶液浸泡处理,种子发芽率最高,为32％;以150 mg/L赤霉素浸泡果梅种子的适宜时间为30 h;在层积时间内,以层积60 d的果梅种子发芽率最高,可达33％;破壳处理可明显提高果梅种子发芽率,可达47％.     

Seed-coat anatomy and proanthocyanidins contribute to the dormancy of Rubus seed

Rubus seed has a deep double dormancy that restricts germination due to seed coat structure and chemical composition. Improved germination of diverse Rubus species required for breeding improved blackberry and raspberry cultivars is partly dependent on the seed coat structure. This study evaluated the seed coat structure of three species with thin (R. hoffmeisterianus Kunth & C. D. Bouché), medium (R. occidentalis L.) and thick (R. caesius L.) seed coats. The three species exhibited distinctive seed-coat cell composition. The very thin testa (0.086 mm) of R. hoffmeisterianus had little exotesta (surface) reticulation; with the meso- and endotesta composed of sclereids of homogenous shape and size. R. occidentalis had a thick testa (0.175 mm) and a highly reticulate exotesta; the meso- and endotesta were composed of several diverse types of sclereids. R. caesius had the thickest seed coat (0.185 mm) but only moderate exotesta reticulation; the meso- and endotesta were composed of large, irregular, loosely arranged sclereids. R. occidentalis, a medium size seed, was the most heavily lignified with seed-coat thickness similar to R. caesius, the largest seed. Proanthocyanidins (PAs) from dry seed of six Rubus species were extracted and quantified by high performance liquid chromatography. R. hoffmeisterianus, a thin only slightly hard seed, had half the PA (0.45 μg/seed) of R. occidentalis with a thick, extremely-hard seed coat and diverse sclereids (1.07 μg/seed). PA content and sclereid composition both appear contribute to seed coat hardness and resulting seed dormancy. The effectiveness of sulfuric acid for Rubus seed scarification is likely due to degradation of PAs in the testa.     

重金属对蒲公英种子萌发及叶片渗透调节物质含量的影响

采用水培法利用发芽和出苗试验,研究不同浓度的重金属Hg2+、Pb2+、Cr3+、Cd2+、Cu2+、Zn2+对蒲公英种子萌发及幼苗生长的影响.结果表明:重金属对蒲公英种子萌发有低浓度的促进效应和高浓度的抑制效应.当重金属浓度很低时不影响种子的发芽指数,随着重金属浓度的提高,发芽指数、发芽势、发芽率均会降低, 叶片内的脯氨酸含量均显著增加.可溶性糖含量呈现先上升后下降的趋势.总体上来看,Hg2+的毒性最强,对蒲公英种子萌发的影响程度依次为Hg2+>Cd2+>Pb2+>Cr3+>Cu2+>Zn2+.     

桃果实缝合线软化的生理原因探讨

为了明确桃果实缝合线软化的原因,采用气相色谱法对大久保桃果实缝合线软化过程中乙烯释放、果胶酶含量、种胚呼吸、矿质元素含量等指标进行了测定。结果表明,在果实症状出现初期,乙烯主要存在于种仁中,并开始向果肉释放,此时缝合线处果胶酶活性最高;种仁的呼吸高峰是在果实缝合线软化后,此时病果果肉、种仁和种壳含水量明显高于正常果;N素含量病果明显高于正常果,干物质含量则相反;种仁充水、呼吸加强,使种仁提早释放乙烯是缝合线软化的主要原因。建议采收前减少灌水和氮肥的施用。     

盐胁迫对无芒雀麦种子发芽势和发芽率的影响

在实验室条件下,模拟土壤盐积状况,在0.2%、0.4%、0.6%、0.8%、1.0%、1.2%、1.4%、1.6%、1.8%NaCl溶液浓度下,进行抗盐性试验,处理草坪植物无芒雀麦,测定发芽数、根数、叶数、根长、叶长等。结果表明:在盐胁迫下,随盐浓度的增加,无芒雀麦的发芽率、发芽指数及活力指数逐渐下降,平均发芽时间随NaCl浓度的增加而变长。胚芽和胚根长度随盐浓度的增加受抑制程度增加,无芒雀麦的根数随盐浓度的增加呈现递减的现象。     

桃果实维管束的分布及解剖研究

 为了解桃果实输导组织分布及结构特征, 以‘大久保’桃果实为试材, 观察了维管束系统的分支体系和分布状况, 并用石蜡切片技术对维管束组织的解剖结构进行了系统观察。结果表明, 桃果实中的维管束分为骨干、分支和毛细3级, 其中骨干维管束又分为种胚维管束、内果皮维管束和中果皮维管束(腹维管束、背维管束及分布在内果皮两侧着生于果柄的维管束) , 分别为种仁、内果皮、中果皮的物质运输通道。种胚维管束韧皮部极其发达, 并伴有三生结构; 内果皮中分布的维管束韧皮部发达; 腹维管束、背维管束粗大且分支较多, 兼具发达的韧皮部及木质部。分支维管束和毛细微管束主要分布在中果皮中。毛细维管束的特点是韧皮部处有腔, 腔体随着果实的发育不断扩大。形态和结构上的不同是与其功能相适应的, 由此推测种仁和内果皮发育需要的营养物质以有机营养为主, 中果皮发育需要的营养物质则涵括有机物、无机物、水分。     

匙叶翼首草不同海拔地区种子活力的研究

采用裂区设计研究了不同海拔地区匙叶翼首草种子在不同处理下的种子活力及最佳的发芽温度、光照等条件,为了大田生产的种子发芽和育苗提供理论指导。结果表明:在不同的处理下,不同海拔地区的翼首草种子经过50℃水浴处理20 min,在暗培养箱25℃恒温下培养,都能极好地提高其种子的发芽率、发芽势、发芽指数等指标;同时,在发芽与育苗试验中选用甘南碌曲双岔海拔较低地区的翼首草种子,种子的活力最高,引种驯化与人工栽培更易于成功。     

Effect of stratification temperature,stratification period and seed coat on seed germination of peach cultivar ‘Sharbati’

Freshly harvested seeds of peach cultivar ‘Sharbati’ were found to be dormant and did not germinate at all. A specific low-temperature stratification treatment was required to overcome seed dormancy. 10° C stratification was found to be the best for breaking seed dormancy. Increased seed germination was recorded when the seeds were after-ripened without seed coats as compared to the seeds after-ripened with seed coats. There was no further increase in germination when seeds without seed coats were stratified beyond 60 days at 10° C, while a significant increase was recorded up to 75 days of stratification in the case of seeds with seed coats. Unstratified seed coats, soaked in water for 72 h, leached out a water-soluble inhibitor, which could suppress the germination of stratified peach seeds without seed coats. When this leachate was bioassayed by a cress-seed germination test, it showed the presence of an inhibitor at Rf 0.7-0.9. Hence, delayed germination of seeds with seed coats may be due to the presence of an inhibitor in seed coats.     

不同浓度茼蒿器官水浸提液对西瓜种子发芽特性的影响

采用0.001、0.01、0.1 g?mL-1的干茼蒿根、茎叶、花水浸提液处理西瓜种子,测定其发芽势、发芽率及胚根鲜质量,研究茼蒿水浸提液对西瓜种子的化感抑制率。结果表明：不同浓度茼蒿器官（根、茎叶、花）水浸提液对西瓜种子萌发有较强的抑制作用,随处理浓度升高,抑制作用越强,发芽势、发芽率、胚根鲜质量均低于对照,因此,茼蒿水浸提液浓度在0.001～0.1 g?mL-1对西瓜种子萌发存在明显的化感作用。     

茄子种子萌发过程中表皮粘膜对种子萌发的影响

通过对六叶茄和中长1号种子吸水率的测定,不同水分梯度种子萌发试验,不同发芽床种子萌发试验,垂直板种子萌发试验以及种子萌发过程中产生的表皮粘膜提取液处理,结果表明,粘膜不阻碍水分进入种子内部;随着种子表皮多余水分的增加,粘膜增厚,种子发芽率降低;以砂床作发芽床,种子不易产生粘膜,发芽率较高。     

Metabolite profiling reveals the involvement of aberrant metabolic changes in Gentiana triflora seed showing poor germination

Gentians are alpine plants and two endemic species, Gentiana triflora and G. scabra, are cultivated as ornamentals in Japan. Because most of the Japanese cultivars are F₁ hybrids, seed germination rate is an important factor for maintaining these cultivars. However, germination rates frequently differ among cultivars. Poor germination is a severe problem for gentian production, although there is almost no difference in their germination period and growth rate. In this study, we compared seed germination rates among three cultivars of G. triflora. A high rate of seed germination was observed in ‘Majel’ (MJ) and ‘Iwate’ (IW), but a low rate was recorded in ‘Iwate-Yumeminori’ (YM). We conducted a targeted metabolome analysis using these cultivars to elucidate the potential cause of inhibited seed germination. Multivariate analysis revealed that the aberrant accumulation of specific amino acids and a decrease in energy metabolites were observed in YM seed. Furthermore, protein concentrations and proteolytic activities in YM seed were lower than in MJ seed. These results imply that energy depletion was the main reason for the decreased rate of germination and that this depletion inhibited processes involved in seed germination, including de novo synthesis of the proteins necessary for germination.     

Developmental problems in over-winter off-season longan fruit. II: Development of pericarp structure

Fruit development was investigated in field and changes in pericarp structure were comparatively studied in over-winter off-season and on-season longan (Dimocarpus longan Lour. cv. Chuliang). The results showed developmental problems including small fruit size, severe fruit cracking and heavy fruit drop in the off-season fruit, although their seed size was not significantly affected compared to the on-season fruit. Anatomical studies showed that off-season longan fruit had a poorly developed pericarp, which was reflected by smaller fresh weight as well as thinner pericarp thickness, thinner spongy tissue, fewer cell layers in the periderm, smaller cell size and fewer cell numbers in the parenchyma tissue at the upper mesocarp, and fewer cell layers in the endocarp. In contrast, the recovery of the sclereids in the mesocarp was higher in the pericarp of the off-season fruit. The poor development of the pericarp in off-season fruit probably caused the small fruit size and severe fruit cracking. It was suggested that the adverse climatic conditions encountered by fruit development in the over-winter off-season longan suppressed cell division and expansion in the pericarp but did not affect sclereid formation.     

环境因素对曼陀罗种子萌发特性的影响

研究了光照、温度、pH以及浸种温度对曼陀罗种子萌发率的影响。结果表明:曼陀罗种子为嫌光种子;种子在温度21～27℃,pH 4～8的范围内都有较高的萌发率;使用40～60℃的温水对曼陀罗种子浸种,萌发率显著提高。     

不同处理方法对荸荠种子发芽的影响

以当年采收的荸荠种子为材料,探讨运用不同的处理方法,如低温层积、摩擦去种皮、98 %浓硫酸浸泡、热水浸泡、不同浓度GA3和6-BA浸泡、不同贮藏方式、不同发芽温度和光照条件以及不同品种等对荸荠种子发芽率、发芽势和发芽指数的影响。结果表明：荸荠种子4 ℃低温水藏48 d后,98 %浓硫酸浸泡10 min+40 ℃水浸泡50 min对提高荸荠种子发芽率效果最好;发芽温度以25 ℃最好,30 ℃下种子不发芽;贮藏方式以湿沙藏最好,其次是水藏;种子在部分光照条件下发芽较好,黑暗条件下发芽率较低,不同品种之间以沙洋荸荠发芽率、发芽势和发芽指数均最高。     

Early growth and development of the olive fruit mesocarp

SUMMARY

We examined growth and development of the ‘Manzanilla’ olive fruit mesocarp in transverse equatorial sections during the first 12 weeks after full bloom (AFB). Sequential sampling and quantitative data provided an integrated view of the formation of this tissue. The mesocarp, or fruit flesh, was formed by relatively isodiametric parenchyma cells with a small number of isolated sclereids. By four weeks AFB a gradient in cell size characteristic of mature olive fruits began to appear. Biweekly measurements of cell size and number indicated that, as in other drupes, both cell division and expansion contribute to initial mesocarp growth. From six weeks AFB, further mesocarp growth was determined solely by cell expansion. Transverse areas of mesocarp and endocarp, also measured biweekly, revealed that both tissues expand in a similar manner until eight weeks AFB, after which mesocarp growth predominated.     

磁场对结球甘蓝种子萌发的影响及机理研究

以结球甘蓝种子为试材,采用正交试验和均匀试验方法,研究了磁场强度、作用时间及处理前种子浸泡时间对各发芽指标的影响以及各影响因素的主次顺序,并对磁场参数中磁场强度和作用时间进行大范围筛选,更进一步从可溶性蛋白含量、丙二醛含量、抗氧化酶活性等方面探讨磁场处理提高种子活力的作用机理。结果表明：适宜的磁场处理可以促进种子萌发,提高种子活力,以20 ℃蒸馏水浸泡8 h 后1 000～3 500 GS 磁场处理1～6 min 为宜,但长时间、大强度磁场处理反而抑制种子萌发;磁场强度为种子萌发的主要影响因子,作用时间和浸泡时间的主次顺序因发芽指标的不同而不同;与对照相比,磁场处理的种子萌发期间可溶性蛋白含量降低或升高的速率、MDA 含量下降的幅度和速率、3 种抗氧化酶活性上升的速率均加快,从而提高种子活力。