共查询到20条相似文献，搜索用时 15 毫秒
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母体对小麦胚的ABA敏感性和种子休眠性的影响 总被引：3，自引：0，他引：3
种子休眠是品种穗发芽抗性的主导因素,休眠特性与母体效应和胚对ABA的敏感性均有密切关系。为了了解母体对小麦胚的ABA敏感性和种子休眠的影响,为抗穗发芽育种提供科学依据,对穗发芽抗性不同的小麦品种及它们正反交F1后代授粉后不同发育阶段的胚进行了ABA敏感性鉴定,并对收获前的籽粒发芽能力进行了测定。结果表明,在种子发育过程中,不同基因型的离体胚萌发能力存在差异,抗穗发芽品种的胚对ABA敏感性明显高于易穗发芽品种,胚对ABA的敏感性与其萌发能力关系密切,随着萌发能力的升高,胚对ABA的敏感性降低。在成熟种子中,F1的休眠性偏向于抗性亲本。尽管成熟种子和胚的休眠表现出一定的母体效应,但母体对发育至成熟过程中胚的ABA敏感性并没有影响。因而,母体对种子休眠的影响可能与胚的ABA敏感性无关。 相似文献
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小麦品种铭贤169是我国黄淮麦区育种研究广泛应用的条锈病诱发材料,但其种子休眠时间过长,不仅影响播种后均匀发芽和生长发育,其收获掉落籽粒也容易导致秋季育种田的生物学混杂。本研究通过筛选其休眠种子与萌发种子的转录组学数据,克隆获得差异表达基因TaJAZ1,并对其生物信息学特性、亚细胞定位、表达模式进行分析,结合解析拟南芥jaz3（与TaJAZ1同源性最高）突变体、TaJAZ1过表达拟南芥和水稻的表型反应。结果表明,TaJAZ1基因编码区全长1 230 bp,可编码409个氨基酸,在不同物种间保守性较强,与野生二粒小麦JAZ1基因的亲缘关系最近;启动子区含有脱落酸响应元件ABRE 和茉莉酸甲酯响应元件CGTCA-motif和TGACG-motif;该基因定位于细胞核和细胞膜,TaJAZ1基因在种子发育中穗发芽时期表达量达到最高,进入成熟时期表达量显著降低;ABA能诱导TaJAZ1基因的表达,ABA处理下过表达拟南芥的萌发率比野生型和jaz3突变体高,ABA信号通路基因AtABI5的诱导量变低;TaJAZ1过表达水稻的萌发率高于受体水稻, ABA处理后,OsABI5的诱导量也降低。以上结果证明,TaJAZ1基因能促进种子萌发,进一步验证其在ABA信号通路中起负调控作用,为改良铭贤169等强休眠性小麦品种提供参考。 相似文献
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不同穗发芽抗性的小麦胚对ABA敏感性及抗性机制研究 总被引：6，自引：2，他引：4
以20个小麦品种为材料,测定了不同穗发芽抗性的小麦品种处于种子发育过程中的胚对ABA敏感性和后熟过程中种子的萌发能力,以揭示小麦对穗发芽的抗性机制。结果表明,在种子发育过程中,不同抗性品种的胚萌发能力和胚对ABA敏感性存在差异。胚萌发能力随胚龄的增加,呈"低～高～低"的变化趋势。扬花后25d到35d的胚萌发势的降幅值在抗穗发芽基因型中所占的比重明显较易穗发芽基因型大。易穗发芽基因型对ABA的敏感性随胚萌发能力的提高而下降,而抗穗发芽的基因型对ABA的敏感性随胚萌发能力的提高则有升有降。因此,胚休眠主要在发育后期获得。红皮易穗发芽品种的成熟胚因脱离母体而提高的萌发势明显较白皮易穗发芽品种的高。品种的成熟胚离体萌发能力越高,则种子休眠期越短。 相似文献
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X. Q. He Y. R. Wang X. W. Hu C. C. Baskin J. M. Baskin Y. Y. Lv 《Grass and Forage Science》2016,71(4):641-648
Leymus chinensis (Trin.) Tzvel. is a perennial grass with high productivity and forage value; however, poor stand establishment, often due to seed dormancy, limits its widespread use for forage production. To investigate the mechanism of seed dormancy and to develop effective methods of improving germination, the contribution of each part of the caryopsis to dormancy was investigated, and a number of single or combined dormancy‐breaking pre‐treatments were conducted using three seed lots. The palea, lemma, pericarp/testa, and endosperm all contributed to seed dormancy. The contribution of each part to dormancy was 23·4%, lemma; 6·2%, palea; 28·4%, pericarp/testa; and 42·0%, endosperm. Hull (palea and lemma) removal, pericarp/testa piercing, and soaking in distilled water or 30% sodium hydroxide (NaOH) significantly decreased the percentage of dormant seeds (i.e. increased germination). Treating hull‐removed and pericarp/testa‐pierced seeds with gibberellic acid (GA3) also significantly decreased the percentage of dormant seeds. Compared with each of the single pre‐treatments, the combined pre‐treatment of pre‐soaking in water for 1 d, then 30% NaOH for 60 min and treating with 300 μm GA3 resulted in the highest germination (89%); and seed viability was 91%. 相似文献
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为探究小麦种子休眠解除期间的成分变化对发芽率的影响,了解种子休眠解除机制,以铭贤169为材料,在收获后不同储藏时间（间隔20 d）取样,通过显微设备观察了种子后熟期间的结构变化,测定了相关生理指标和成分,以探究铭贤169种子休眠性原因。结果表明,铭贤169种子休眠解除过程中,种皮细胞结构、组织结构、淀粉粒结构、蛋白基质等均发生变化,淀粉含量、粒径、糊化特性、热稳定性随贮藏时间延长变化显著。铭贤169的离体胚在花后25 d就具有发芽能力,但种子在花后35 d仍处于休眠。收获后熟期间,种胚活性、种子吸水率、含水量、淀粉含量、淀粉糊化谷值粘度和峰值时间、热稳定性逐步上升,与发芽率正相关。A型淀粉粒表面破损,淀粉粒与蛋白质结合紧密,种皮结构松散;淀粉粒径、淀粉酶活性、可溶性糖含量和沉降值减小;面筋和粗蛋白含量变化不大。推测铭贤169种子的休眠性与种子母体成分有关,休眠解除期间发芽率变化受种皮结构、淀粉的分解程度、淀粉粒与蛋白质的结合方式、可溶性糖含量、淀粉含量和性质以及淀粉酶活性等因素影响。 相似文献
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Reduction of Seed Dormancy in Echinacea pallida (Nutt.) Nutt. by In-dark Seed Selection and Breeding
Strong seed dormancy has been an obstacle for field production of Echinacea species. Previous research on overcoming Echinacea seed dormancy has been extensive and focused on treatment methods, which involve time and expense, and are incompatible with organic production if synthetic chemicals are used. We have attempted to genetically reduce seed dormancy through selection and breeding in Echinacea, by using Echinacea pallida as a model species. Three accessions were used in this study. Nine parent plants of each accession selected from early, in-dark germinated seeds (in-dark plants) or from late, in-light seeds (in-light plants) were planted and grouped by accession and germination treatment method for seed production through a polycross method. Germination tests indicated that these in-dark plants produced seed (in-dark seed) with significantly reduced seed dormancy when tested under light or dark condition in comparison to the seed of the in-light plants (in-light seed). Among the three accessions, the in-dark seed germinated at much higher rates than did the in-light seed, more than 2× at 25 °C under light and up to an 83× increase in darkness, and up to an 8× increase over the corresponding parental seed lots under comparable germination conditions. In addition to these increases in germination, the in-dark seed showed early and synchronized germination as compared to the in-light seed. Since these results were achieved through only one cycle of selection and breeding, they strongly suggest that we have developed a very effective method for modifying seed dormancy in Echinacea. 相似文献
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Physiological regulation of potato tuber dormancy 总被引：1，自引：0，他引：1
Jeffrey C. Suttle 《American Journal of Potato Research》2004,81(4):253-262
At harvest, potato (Solanum tuberosum L.) tubers are dormant and will not sprout. As the period of postharvest storage is extended, tuber dormancy is broken and sprout growth commences. The loss of tuber dormancy and onset of sprout growth is accompanied by numerous biochemical changes, many of which are detrimental to the nutritional and processing qualities of potatoes. Endogenous hormones have been proposed to play a significant role in tuber dormancy regulation. The involvement of all major classes of endogenous hormones in tuber dormancy is reviewed. Based on available evidence, it is concluded that both ABA and ethylene are required for dormancy induction, but only ABA is needed to maintain bud dormancy. An increase in cytokinin sensitivity and content appear to be the principal factors leading to the loss of dormancy. Changes in endogenous IAA and GA content appear to be more closely related to the regulation of subsequent sprout growth. 相似文献
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Confirmation of Novel Quantitative Trait Loci for Seed Dormancy at Different Ripening Stages in Rice
Seed dormancy contributes resistance to pre-harvest sprouting.Effects on respective quantitative trait loci (QTLs) for dormancy should be assessed by using fresh seeds before germinability altered through storage.We investigated QTLs related to seed dormancy using backcross inbred lines derived from a cross between Nipponbare and Kasalath.Four putative QTLs for seed dormancy were detected immediately after harvest using composite interval mapping.These putative QTLs were mapped near C1488 on chromosome 3 (qSD-3.1),R2171 on chromosome 6 (qSD-6.1),R1245 on chromosome 7 (qSD-7.1) and C488 on chromosome 10 (qSD-10.1).Kasalath alleles promoted dormancy for qSD-3.1,qSD-6.1 and qSD-7.1,and the respective proportions of phenotypic variation explained by each QTL were 12.9%,9.3% and 8.1%.We evaluated the seed dormancy harvested at different ripening stages during seed development using chromosome segment substitution lines (CSSLs) to confirm gene effects.The germination rates of CSSL27 and CSSL28 substituted with the region including qSD-6.1 were significantly lower than those of Nipponbare and other CSSLs at the late ripening stage.Therefore,qSD-6.1 is considered the most effective novel QTL for pre-harvest sprouting resistance among the QTLs detected in this study. 相似文献
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《Field Crops Research》1988,18(4):271-278
Wheat (Triticum aestivum L.) cultivars differ in resistance to preharvest sprouting, which can occur when rains precede harvest. The objective of this study was to determine of sprouting resistance was related to endogenous levels of embryonic abscisic acid (ABA) and/or to the degree of embryonic sensitivity (capability of ABA to block embryonic germination) to exogenously applied ABA. Embryonic ABA levels and sensitivity were compared during the grain development period in 1983 and 1984 in a sprouting-resistant cultivar, ‘Brevor’, and a susceptible cultivar, ‘Greer’. The ABA levels were influenced by environment and year but not by cultivar, except at the soft-dough/ hard-dough transition stage of development in both years and at hard-dough stage in 1983. At those stages, Brevor had higher levels of free ABA than Greer. Embryonic ABA level and rate of germination of dissected embryos in water were not related, but the rate of germination was reduced by exogenous ABA (5×10−5M), and was reduced more in Brevor than in Greer. Differences in embryonic sensitivity to ABA, modulated by environmental conditions during the grain-filling period, may contribute to cultivar differences in resistance to preharvest sprouting. 相似文献
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Hiroyuki Shiratsuchi Youichi Ohdaira Hiromichi Yamaguchi Akari Fukuda 《Plant Production Science》2017,20(2):183-192
This study aimed to determine the appropriate steam treatment conditions, using a steam nursery cabinet, to break the dormancy of Japanese rice cultivar seeds exhibiting various dormancy levels. The influence of the temperature and duration of the steam treatments on the germination percentage and germination rate was investigated. In highly dormant ‘Takanari’ seeds, the steam treatment at 40 °C for 7 d increased the germination percentage and decreased the 50% germination time (T50S; based on seed number); this treatment was as effective as the dry heat treatment at 50 °C for 7 d. For the medium dormant ‘Moeminori’ and ‘Hitomebore’ seeds, the steam treatment at 40 °C for 5 d decreased T50S sufficiently and more effectively than did the dry heat treatment at 50 °C for 7 d. For the slightly dormant ‘Moeminori’ seeds, the steam treatment at temperatures ranging from 24 °C to 40 °C for 7 d decreased T50S without a corresponding decrease in germination percentage to <90%. For the non-dormant ‘Moeminori’ and ‘Takanari’ seeds, the same steam treatments had no, or a little if any, useful effect on the germination percentage and T50S. Therefore, we concluded that, for the highly dormant seeds, steam treatment at 40 °C for 7 d was appropriate. Moreover, for less dormant seeds, steam treatment at 40 °C for 5 d was appropriate, and the steam treatment was not necessary for the non-dormant seeds. 相似文献
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为了解云南铁壳麦(Triticum aestivum ssp.yunnanense)的穗发芽抗性及其机制、筛选抗性材料,以白粒推广良种云麦53号为对照,采用整穗发芽、整粒发芽及分子功能标记的方法,鉴定了55份云南铁壳麦的穗发芽抗性及种子的休眠特性,分析了发芽指数(germination index,GI)在穗发芽抗性级别不同的材料间、分子功能标记基因等位变异间的差异及籽粒发芽率(germination percent,GP)在不同休眠级别的材料间的差异。结果表明,以整穗发芽率(spikes germination rate,SGR)为鉴定指标,在对照云麦53号的SGR达76.2%的前提下,云南铁壳麦除1份材料SGR为2%外,其他材料的SGR都为0,与对照相比,对穗发芽的抗性都很强。以GI为鉴定指标,供试云南铁壳麦对穗发芽的抗性则较弱,抗性材料较少,GI为15.5%～72.8%(对照的GI为65.7%),GI在抗性级别不同的材料间明显不同。以籽粒发芽率为依据,云南铁壳麦的种子休眠性可分为休眠、中度休眠、浅休眠和无休眠4级,GP在不同休眠级别的材料间也显著不同。用STS功能标记 Vp1B3扩增出A带(652 bp)、C带(无带)的材料,其GI均与扩增出B带(569 bp)材料的GI有明显差异;用标记Vp1A3扩增出B带(170 bp)材料的GI与C带(无带)材料的GI也有明显差异,其他3个功能标记( Tasdr-B1、 Tamyb10D1、 Tamyb10D)扩增到不同带型材料的GI则无明显的不同,用分子标记获得的结果不能解释云南铁壳麦的穗发芽抗性或种子休眠特性的变化。 相似文献
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Preharvest sprouting occurs following rainfall after maturity and reduces grain quality and value. Dormancy at maturity is a trait frequently used by wheat breeders to improve tolerance to sprouting. To determine the environmental influence on the predicative relationship between dormancy at maturity and improved preharvest sprouting tolerance, dormancy (germination index) at maturity and grain quality (falling number) at maturity and then, after rainfall, was measured over three seasons. Based on the results it was possible to draw three main conclusions. Firstly, genotypes with strong dormancy (germination index <0.20) which have the embryo and seed coat component of dormancy maintained a falling number >300 s at all sites and seasons for the 2-month period after maturity despite receiving up to 122 mm of rain. Adequate preharvest sprouting tolerance also occurred in dormant genotypes, with just the embryo component; in all but the most severe conditions. Secondly, though the effect of environment and interaction of genotype and environment was significant, the G by E interaction did not account for a large proportion of the variation (<6%) in sprouting tolerance (measured by falling number after rainfall) or change the relative rankings of preharvest sprouting tolerance. Finally, other defects associated with rainfall during grain filling such as black point and fungal staining may slightly reduce dormancy estimates and preharvest sprouting tolerance. For this reason grain defects need to be improved in parallel with preharvest sprouting tolerance. In conclusion, strong dormancy provides a reliable source of preharvest sprouting tolerance in the field. 相似文献
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本文研究了风干处理、发芽温度条件及果壳阻抑对芸薹属三个种种子休眠与萌发的影响,结果表明:(1)风干处理可使花后不同天数的种子完成后熟作用,促进种子的萌发,其破眠效果,尤以休眠浅的甘蓝型油菜为显著;(2)果壳对种子发芽有明显的阻抑作用,产生“强迫休眠”现象,其对种子的诱眠率,以休眠浅的甘蓝型油菜高于休眠深的芥莱型油菜;(3)油菜种子采收后先经风干,再在变温条件下发芽,其破眠效果高于单一风干或变温发芽。同时能有效地解除开花后20天以上幼嫩种子的休眠。 相似文献
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Two hundred groundnut (Arachis hypogaea L.) germplasm accessions and 21 cultivars belonging to the Spanish group (ssp. fastigiata var. vulgaris) were screened for pod loss due to sprouting of seed in the field. Some cultivars were also tested for germination of the fresh-seed with or without testa and treated or untreated with ethrel or abscisic acid (ABA). Large variation in pod loss due to in situ sprouting of seed, and fresh-seed dormancy (FSD) was found among the accessions and cultivars. Fresh-seed dormancy index (FSDI) varied from 2% in Chico to 88% in ICGS 44 (the check with high FSD). Cultivars with an FSDI value of less than 10% showed more pod loss in situ than the cultivars with high FSDI. Thus pod loss due to in situ sprouting increased with a decrease in FSDI. Cultivar SB XI did not show any in situ sprouting or pod loss. A direct relationship (r, 0.86**) existed between fresh-seed germination of accession/cultivar in the laboratory and the percentage of its plants with sprouted seed in the field. Seed of two Spanish cultivars ICGS 11 (dormant) and GG 2 (non-dormant) when tested for germination after treatment with ethrel or ABA at various seed development stages showed different germination response to these chemicals. Seed of GG 2 showed up to 40% germination even at an early stage (S1) of seed development, whereas the seed of ICGS 11 responded to the ethrel only at maturity (S4). Regulation of FSD appeared to be more under the control of the testa than the cotyledons. The variation in the degree of in situ sprouting can be used for breeding Spanish cultivars with various desirable levels of FSD. 相似文献
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Preharvest sprouting is common in cereals that lack grain dormancy if maturing grain is exposed to rain. Over three successive seasons wheat genotypes with a range of dormancy levels, were exposed to moisture stress and periods of high temperature stress (>30 °C) in controlled field trials. Dormancy assessments were based on a germination index of hand threshed grain throughout grain filling. There were three main results. First, moisture stress combined with consistently high temperature during grain filling was associated with induced dormancy in Cunderdin, (germination index of 0.41) in a normally non-dormant genotype (germination index normally >0.80), but no additional dormancy in DM 2001, a dormant genotype (germination index normally <0.10). In contrast sudden heat shocks (>30 °C max. for >12 days) at 30–50 days post-anthesis reduced dormancy, germination index increase of 0.42 on average across five genotypes. Secondly, whilst dormancy was affected by moisture and heat stress, genotypes maintained their relative rankings across environments and genotype had the most effect on dormancy (70–92% of the variation in germination index) with DM 2001 and DH 22 more dormant than DH 56, DH 45 and Cunderdin. Finally, the effect of environment was different for different genotypes; those with partial dormancy (germination index usually 0.20–0.50, DH 56 and DH 45) were most influenced by the environmental conditions with germination indexes ranging from 0.06 to 0.85 depending on environment. Consequently avoidance of high temperatures, moisture stress, and maturity × stress interactions, are important prerequisites in screening for genotypes with genetic differences in dormancy. 相似文献
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为了解黄腐酸、褪黑素、水杨酸三种浸种剂对硫酸盐胁迫下小麦种子萌发期耐盐性的调节效应,分别采用不同浓度的黄腐酸(0.5、1.0和1.5 g·L-1)、褪黑素(0.01、0.05和0.10 mmol·L-1)、水杨酸(0.1、0.5和1.0 mmol·L-1)对小麦进行浸种处理,随后与未处理的小麦种子一并采用100 mmol·L-1 Na2SO4溶液培养,测定各处理下小麦种子萌发期的生长生理指标,并通过主成分分析综合评价其耐盐性。结果表明,0.5～1.5 g·L-1的黄腐酸、0.01～0.10 mmol·L-1褪黑素、0.1～0.5 mmol·L-1水杨酸浸种均提升了小麦根系活力、体内抗氧化酶活性,降低了小麦体内超氧阴离子自由基■产生速率及丙二醛(MDA)含量,缓解了盐分对小麦种子萌发的胁迫程度,增强了小麦种子萌发期的耐盐性,促进了小麦的萌发生长。其中,1.5 g·L-1的... 相似文献
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研究了种子包衣对微胚乳玉米种子萌发时生理生化变化的影响。结果表明：微胚乳玉米种衣剂(MESC)包衣可提高种子萌动时赤霉素(GA3)与脱落酸(ABA)含量的比例,提高种子生长素(IAA)和可溶性总糖的含量,促进蛋白质的形成和油脂的降解,加速氨基酸的利用。适乐时种衣剂(FDXN)包衣提高了ABA的含量,降低可溶性总糖含量,减缓油脂的降解和氨基酸的利用,最终抑制种子的发芽。微胚乳玉米种衣剂包衣可促进微胚乳玉米种子发芽过程中的生化变化过程,从而促进种子发芽。 相似文献
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为探讨6-苄基腺嘌呤（6-BA）浸种对HgCl2胁迫下小麦种子萌发及其幼苗生长的缓解作用,以3个小麦品种为材料,研究了不同浓度6-BA浸种对200 mg·L-1HgCl2胁迫下小麦种子发芽、幼苗生长、抗氧化酶活性、可溶性蛋白和丙二醛含量的影响。结果表明,200 mg·L-1HgCl2处理后,3个小麦品种种子的发芽势、发芽率、根长、芽长和鲜重降低,幼苗的抗氧化酶活性和可溶性蛋白含量降低,丙二醛含量增加。一定浓度6-BA浸种可以缓解HgCl2胁迫对小麦种子萌发的抑制作用,但对小麦的根长、芽长和鲜重的影响因小麦品种而不同。HgCl2胁迫下,3个小麦品种幼苗的SOD、POD活性和可溶性蛋白含量随着6-BA浓度的增加均基本呈先升高后降低的趋势,最佳6-BA浓度因品种而不同;3个小麦品种的MDA含量均呈先降低后升高的趋势,以6-BA浓度为15 mg·L-1时MDA含量最低。说明一定浓度6-BA浸种能够缓解HgCl2胁迫对小麦种子萌发和幼苗生长的毒害作用,但最佳6-BA浓度因小麦品种的不同而不同。 相似文献