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1.
Understanding the growth and physiological responses of rice to upland conditions would be helpful for designing treatments
to improve the tolerance of rice under a rainfed system. The objective of this study was to investigate the initiation, elongation
and membrane stability of seminal, lateral and adventitious roots of upland rice after 9-d upland condition treatment. Compared
with control roots under waterlogged conditions, upland water deficiency conditions favor seminal and lateral root growth
over adventitious root growth by accelerating seminal root elongation, promoting lateral root initiation and elongation, and
reducing the elongation and number of adventitious roots. Enhanced total root number and length resulted in increase of total
root dry weight and thereby increasing the root-to-shoot ratio. Organic compound leakage from seminal root tips and adventitious
roots increased progressively to some extent with upland culture duration, while significant increases in semial root tips
were the consequence of loss of membrane integrity caused by the upland-condition enhanced growth.
Project (No. G1999011700) supported by National Key Basic Research Special (863) Foundation of China 相似文献
2.
研究了向日葵种子根的向光反应特性及光照时间、光照强度IAA和GA3对其向光性的影响。结果表明:(1)向日葵种子根表现为负向光性倾斜生长;(2)在2~8h的光照时间内,向日葵种子根的负向光性与光照时间成正比;(3)在5~25 lx的光强范围内,向日葵种子根的负向光性与光强成正比;(4)0~10-4mol.L-1的IAA可促进根的伸长和增强其负向光性反应,随着IAA浓度的升高,向日葵种子根的负向光性反应消失,生长也受到抑制;(5)10-5~10-4 mol.L-1的GA3能促进向日葵种子根的伸长,但对其负向光性无明显影响。 相似文献
3.
Disparity in the root morphology of six rice (Oryza sativa L.) genotypes varying in potassium (K) efficiency was studied with three K levels: 5 mg/L (low),10 mg/L (moderate) and 40 mg/L (adequate) in hydroponic culture.Morphological parameters included root length,surface area,volume and count of lateral roots,as well as fine (diameter<0.2 mm) and thick (diameter>0.2 mm) roots.The results indicate that the root growth of all genotypes was reduced under low K,but moderate K deficiency increased the root length of the efficient genotypes.At deficient and moderate K levels,all the efficient rice genotypes developed more fine roots (diameter<0.2 mm) than the inefficient ones.Both fine root count and root surface area were found to be the best parameters to portray K stress in rice.In accordance with the root morphology,higher K concentrations were noted in shoots of the efficient genotypes when grown at moderate and deficient K levels,indicating that root morphology parameters are involved in root uptake for K and in the translocation of K up to shoots.K deficiency affected not only the root morphology,but also the root ultra-structure.The roots of high-efficient genotypes had stronger tolerance to K deficient stress for root membrane damage,and could maintain the developed root architecture to adapt to the low K growth medium. 相似文献
4.
稀土元素(La~(3+))在10~(-8)～10~(-5)mol/L浓度范围内,对绿豆下胚轴切段不定根形成(ARF)有促进作用。10~(-5)mol/LLa3~+与10~(-4)mol/LIBA混合处理时的生根数比用IBA处理的增加20％,即表现出协同效应,La~(3+)在不定根形成中的0～24h内处理时促进作用较大。这说明在ARF的诱导期和起始早期外施适当浓度的La~(3+)有利于根原基形成,并促进不定根形成。 相似文献
5.
6.
中药王不留行的组织培养技术初探 总被引：1，自引：0，他引：1
选取王不留行饱满种子培养无菌苗,用无菌苗的茎和叶作为外植体,分别接种MS基本培养基外加激素NAA和6-BA诱导愈伤组织和不定芽,使用1/2MS培养基,附加IBA或NAA进行不定芽的生根实验,最后炼苗和移栽.实验结果表明王不留行的最优组织培养方案:种子用0.1%升汞消毒8m in,无菌湿脱脂棉催芽,茎和叶作为外植体,使用MS 0.1mg/L NAA 0.1mg/L 6-BA诱导愈伤组织和不定芽,1/2MS 0.15mg/L NAA诱导植株生根. 相似文献
7.
一氧化氮(NO)是植物体内重要的生物活性分子.实验表明,它可以通过酶促和非酶促途径而产生,它参与种子萌发、叶扩张、根伸长、侧根形成、抑制下胚轴伸长、细胞凋亡以及植物抗逆反应等植物生长发育的众多生理过程.本文着重论述NO在植物生长发育中的作用. 相似文献
8.
桐花树嫩叶浸出液对绿豆下胚轴不定根生长的影响 总被引：1，自引：0，他引：1
本试验研究了桐花树嫩叶浸出液对绿豆下胚轴不定根生长的影响.七个浓度梯度处理分别是:原液(0.078 9 g/mL)、稀释5倍(0.0157 8 g/mL)、稀释10倍(0.007 89 g/mL)、稀释15倍(0.005 26 g/mL)、稀释20倍(0.003 95 g/mL)、稀释30倍(0.002 63 g/mL)、稀释40倍(0.001 97 g/mL),以蒸馏水为对照组.分别简记为T1、T2、T3、T4、T5、T6、T7、CK.结果表明:T1～T6组对绿豆下胚轴不定根数目和生根范围均有显著促进作用,且随浸出液浓度的增大而呈上升趋势,其中T1、T2组的不定根数目和生根范围均显著大于其他组;T4和T5组的不定根根粗为最大,且显著大于其他组;T4组的不定根最长根长、鲜重和干重最大,分别比对照组显著提高14.69%、30.00%和55.56%.试验表明,桐花树嫩叶浸出液对绿豆下胚轴不定根生长具有较明显的化感效应,表现为过高浓度起抑制作用,较高浓度起促进作用,而过低浓度的促进效果不明显. 相似文献
9.
Li QY Niu HB Yin J Shao HB Niu JS Ren JP Li YC Wang X 《Journal of Zhejiang University. Science. B》2010,11(11):862-870
A transgenic barley line (LSY-11-1-1) with overexpressed Phalaris coerulescens thioredoxin gene (PTrx) was employed to measure the growth, protein oxidation, cell viability, and antioxidase activity in barley roots during germination
on the presence of 2 mmol/L AlCl3 on filter paper. The results show that (1) compared with the non-transgenic barley, LSY-11-1-1 had enhanced root growth,
although both were seriously inhibited after AlCl3 treatment; (2) the degree of protein oxidation and loss of cell viability in roots of LSY-11-1-1 were much less than those
in roots of non-transgenic barley, as reflected by lower contents of protein carbonyl and Evans blue uptakes in LSY-11-1-1;
(3) activities of catalase (CAT), glutathione peroxidase (GPX), ascorbate peroxidase (APX), and glutathione reductase (GR)
in LSY-11-1-1 root tips were generally higher than those in non-transgenic barley root tips, although these antioxidase activities
gave a rise to different degrees in both LSY-11-1-1 and non-transgenic barley under aluminum stress. These results indicate
that overexpressing PTrx could efficiently protect barley roots from oxidative injury by increasing antioxidase activity, thereby quenching ROS caused
by AlCl3 during germination. These properties raise the possibility that transgenic barley with overexpressed PTrx may be used to reduce the aluminum toxicity in acid soils. 相似文献
10.
Yun Wu Yi-ping Xia Jia-ping Zhang Fang Du Lin Zhang Yi-di Ma Hong Zhou 《Journal of Zhejiang University. Science. B》2016,17(11):892-904
Bulblet development is a problem in global lily bulb production and carbohydrate metabolism is a crucial factor. Micropropagation acts as an efficient substitute for faster propagation and can provide a controllable condition to explore bulb growth. The present study was conducted to investigate the effects of humic acid (HA) on bulblet swelling and the carbohydrate metabolic pathway in Lilium Oriental Hybrids ‘Sorbonne’ under in vitro conditions. HA greatly promoted bulblet growth at 0.2, 2.0, and 20.0 mg/L, and pronounced increases in bulblet sucrose, total soluble sugar, and starch content were observed for higher HA concentrations (≥2.0 mg/L) within 45 d after transplanting (DAT). The activities of three major starch synthetic enzymes (including adenosine 5′-diphosphate glucose pyrophosphorylase, granule-bound starch synthase, and soluble starch synthase) were enhanced dramatically after HA application especially low concentration HA (LHA), indicating a quick response of starch metabolism. However, higher doses of HA also caused excessive aboveground biomass accumulation and inhibited root growth. Accordingly, an earlier carbon starvation emerged by observing evident starch degradation. Relative bulblet weight gradually decreased with increased HA doses and thereby broke the balance between the source and sink. A low HA concentration at 0.2 mg/L performed best in both root and bulblet growth. The number of roots and root length peaked at 14.5 and 5.75 cm, respectively. The fresh bulblet weight and diameter reached 468 mg (2.9 times that under the control treatment) and 11.68 mm, respectively. Further, sucrose/starch utilization and conversion were accelerated and carbon famine was delayed as a result with an average relative bulblet weight of 80.09%. To our knowledge, this is the first HA application and mechanism research into starch metabolism in both in vitro and in vivo condition in bulbous crops. 相似文献
11.
Xing CH Zhu MH Cai MZ Liu P Xu GD Wu SH 《Journal of Zhejiang University. Science. B》2008,9(3):261-264
To investigate the Fe2 effects on root tips in rice plant, experiments were carded out using border cells in vitro. The border cells were pre-planted in aeroponic culture and detached from root tips. Most border cells have a long elliptical shape. The number and the viability of border cells in situ reached the maxima of 1600 and 97.5%, respectively, at 20～25 mm root length. This mortality was more pronounced at the first 1～12 h exposure to 250 mg/L Fe2 than at the last 12～36 h. After 36 h, the cell viability exposed to 250 mg/L Fe2 decreased to nought, whereas it was 46.5% at 0 mg/L Fe2 . Increased Fe2 dosage stimulated the death of detached border cells from rice cultivars. After 4 h Fe2 treatment, the cell viabilities were≥80% at 0 and 50 mg/L Fe2 treatment and were <62% at 150, 250 and 350 mg/L Fe2 treatment; The viability of border cells decreased by 10% when the Fe2 concentration increased by 100 mg/L. After 24 h Fe2 treatment, the viabilities of border cells at all the Fe2 levels were <65%; The viability of border cells decreased by 20% when the Fe2 concentration increased by 100 mg/L. The decreased viabilities of border cells indicated that Fe2 dosage and treatment time would cause deadly effect on the border cells. The increased cell death could protect the root tips from toxic harm. Therefore, it may protect root from the damage caused by harmful iron toxicity. 相似文献
12.
Comparative mapping of QTLs for Al tolerance in rice and identification of positional Al-induced genes 总被引：2，自引：0，他引：2
INTRODUCTION Aluminum (Al) toxicity is one of the mostimportant yield-limiting factors for crop grown onacid upland and lowland acid sulphate soils (IRRI,1978). Al toxicity results in a reduced and damagedroot system, which in turn causes the affectedplants to be susceptible to drought stress and min-eral nutrient deficiencies (Foy, 1988). The physio-logical and biochemical mechanisms of the toxiceffect of Al on root elongation had been extensivelyinvestigated (Matsumoto, 2000). T… 相似文献
13.
Aluminum (Al) toxicity is the major factor limiting crop productivity in acid soils. In this study, a recombinant inbreed line (RIL) population derived from a cross between an A1 sensitive lowland indica rice variety IR1552 and an Al tolerant upland japonica rice variety Azucena, was used for mapping quantitative trait loci (QTLs) for A1 tolerance. Three QTLs for relative root length (RRL) were detected on chromosome 1, 9, 12, respectively, and I QTL for root length under Al stress is identical on chromosome I after one week and two weeks stress. Comparison of QTLs on chromosome 1 from different studies indicated an identical interval between C86 and RZ801 with gene(s) for Al tolerance. This interval provides an important start point for isolating genes responsible for A1 tolerance and understanding the genetic nature of Al tolerance in rice. Four Al induced ESTs located in this interval were screened by reverse Northern analysis and confirmed by Northern analysis. They would be candidate genes for the QTL. 相似文献
14.
YANG Xiao-cheng DING Jian-ping WANG Bo-chu 《重庆大学学报(英文版)》2007,6(4):227-230
The root development of Actinidia chinensis plantlets was studied in exposure to environmental stress of mechanical vibration at respectively 1 Hz, 2 Hz, 3 Hz, 4 Hz and 5 Hz. The plantlets exposed to vibration stimuli at all those frequencies have a larger total number and a larger total length of roots and a smaller permeability of root plasma-membrane, compared with those cultivated in an environment without vibration stress. Vibration at respectively 1 Hz, 2 Hz, 3 Hz and 4 Hz enhances root activity and the 3 Hz vibration is the most favorable. There is an obvious negative correlation between root activity and permeability of root plasma-membrane. The effects may be explained by the likelihood that mechanical vibration at an appropriate frequency facilitates roots’ absorbing water and minerals which are indispensable to inducing and synthesizing in roots some active substances favorable to growth. Nevertheless, overstress damages the integrity of root plasm-membrane, increases the permeability, and results in the disability of protecting root cells. 相似文献
15.
李海生 《广东教育学院学报》2005,25(3):74-76
通过水培方法,就环境中不同铜离子水平下茶苗对铜的吸收与累积进行了研究.结果表明:茶苗根、茎中铜含量均随着铜处理浓度的增加而明显增加,而叶中含量影响不大.各处理下铜在茶苗各部位含铜量大小依次为根>茎>叶.从整株植物来看,随着铜处理浓度的增加,铜在根部的积累量增加,在茎和叶的积累量趋于下降.适量的铜有助于茶苗根、茎、叶对磷的吸收,但超过一定限度,则茶苗含磷量下降. 相似文献
16.
烯效唑的生理效应及其在水稻上的应用 总被引：3，自引：0，他引：3
瞿宏杰 《襄樊职业技术学院学报》2004,3(6):23-24,9
烯效唑是一种高效低毒的植物生长延缓剂，其作用机理是阻碍GA的生物合成，从而延缓植物生长。烯效唑对水稻具有控长、壮秆、抗倒、抗逆、增产等作用。 相似文献
17.
Ridge culture is a special conservation tillage method, but the long-term influence of this tillage system on soil aggregate-size stability in paddy fields is largely unknown in southwest of China. The paper is to evaluate soil aggregate stability and to determine the relationship between soil organic carbon （SOC） and soil aggregate stability. Soil samples at 0 cm-20 cm layer were adopted from a long-term （16 a） field experiment including conventional tillage： plain culture, summer rice crop and winter upland crop under drained conditions （PUR-r）; and conservation tillage： ridge culture without tillage, summer rice and winter fallow with floodwater layer annually （NTR-f）, winter upland crop under drained conditions （NTR-r）, and wide ridge culture without tillage, summer rice crop and winter upland crop under conditions （NTRw-r）, respectively. Different pretreatments, such as slaking in fast wetting, wetting and subsequent slaking, were applied to simulate the breakdown mechanisms of aggregates in paddy soil. The results show that soil particles contents were mainly consisted of silt （0.050 mm to 1.000 mm） in fraction of 42.9% to 51.2%, sand （0.050 mm to 0.001 mm） in fraction of 28.0% to 31.8%, and clay （〈0.001 mm） in fraction of 17.9% to 25.4%. The amount of aggregate-size was greatly observed in fraction of 2.000 mm-6.720 mm under ridge culture in paddy soil （more than 50$） under slaking and wetting pretreatment. The proportion of soil macro-aggregates （〉0.250 mm） in conservation tillage was greatly higher than that in conventional tillage under subsequent fast slaking treatment. Minimal differences of aggregate stability between slaking in fast wetting and wetting were observed, while significant differences were found between ridge culture and plain culture. The aggregate stability under slaking treatment ranked in the order of NTR-r〉NTRw-r〉 NTR-f 〉 PUR-r, while under wetting was NTRw-r 〉 NTR-r 〉 NTR-f 〉PUR-r. There was a positive correlation between the aggregate stability and SOC concentration under wetting, and a low correlation was observed under slaking pretreatment. Soil exposure with tillage and lack of rice/rape-seed stubble inputs caused declines in aggregation and organic carbon, both of which make soil susceptible to water erosion. Adoption of ridge culture with no-tillage integrated with crop rotation and stubble mulch significantly altered soil organic concentration. It was a valuable conservation practice for soil aggregation and soil organic carbon sequestration on paddy soil. 相似文献
18.
张媛华 《渭南师范学院学报》2007,22(2):47-49
研究了硝普纳（Sodium Nitroprusside，SNP）对黄瓜子叶不定根发生的影响．结果表明，SNP促进黄瓜子叶不定根发生的最适浓度和最佳苗龄分别为50μmol／L和3d龄，最适浓度SNP对3d龄黄瓜子叶不定根发生促进效果最好，同时还对子叶近轴面的放置进行了研究，表明子叶近轴面是否向上对生根没有影响． 相似文献
19.
研究了不同浓度铅胁迫下补血草种子萌发及幼苗的膜透性,结果表明:铅胁迫对补血草的种子萌发具有低浓度下的激活效应和高浓度下的抑制效应;对幼苗苗长具有胁迫初期低浓度下的激活效应,随着胁迫时间的延长,转而表现为抑制效应,对幼苗根长具有显著的抑制效应.幼苗的生长状况比种子萌发更能体现铅毒性的大小.而根长的变化可作为植物受重金属毒性影响的一个重要指标.幼苗的膜透性的影响是随着铅浓度的增加,膜的通透性增加,选择通透的能力下降. 相似文献
20.
稀土对菊花试管苗生长有明显影响。添加稀土后试管苗生长速度快,,根粗苗壮,根冠比大,但根数少。20ppm浓度稀土明显抑制菊花试管苗的株高,对根无抑制作用。50ppm浓度稀土对试管苗的茎、叶、根生长都有促进作用。 相似文献