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1.
《Plant Production Science》2013,16(3):281-288
AbstractDeep penetration of an axile root is one of the important factors that allow crops to form deep root systems. In this study, the nodes from which the deepest penetrated roots had emerged were examined at the heading stage in upland rice and maize grown in large root boxes and in the field. Both experiments were designed to measure the direction, length, and rooting nodes of each root. In maize, the growth angles of axile roots increased with vertical elongation as rooting nodes acropetally advanced. The roots that emerged from the lower nodes, namely from coleoptilar to the second node, exhibited conspicuously horizontal elongation in the field, reaching 2.3 m in width at the maximum. The roots that emerged from higher than the fifth node were too short to penetrate deeply. Thus, these roots became the deepest root in less or no probability under field conditions. On the other hand, the fourth nodal root, which had an intermediate growth angle and length, had the highest probability. In upland rice, the deepest roots emerged from the nodes lower than the forth node on the main stem in the root boxes. In the field, however, the deepest roots emerged at later stages, that is, the roots from the middle nodes on the main stem and from the low nodes on the primary and secondary tillers were the deepest roots. Five out of nine of the deepest roots were from the prophyll nodes in three field-grown upland rice. The deepest roots from the same plant were estimated to have emerged and grown at approximately the same stage. 相似文献
2.
《Plant Production Science》2013,16(4):242-247
SummaryPenetration of the roots deep into soil layer (deep roots) may alleviate growth inhibition under various soil stress conditions. In this study, the nodes from which deep roots had emerged were examined at the heading stage in rice and maize grown in a 2 m long tube. The effect of soil mechanical stress on the rooting nodes of deep roots was also examined. The roots that emerged in a relatively early growth stage, that is, the roots from coleoptilar, 1st and 2nd node in rice, and the seminal root and roots from the coleoptilar, 1st and 2nd nodes in maize, penetrated into the deep soil layer. The node which produced the highest number of deep roots was the 1st node in rice and the coleoptilar node in maize. Seminal root of rice and seminal adventitious roots of maize did not penetrate into the deep soil layer although they emerged at an early growth stage. In the rice root system, the nodal roots, emerged from the upper portion of the node, tended to penetrate deeper than the nodal roots emerged from the lower portion of the same node. Soil compaction did not affect these tendencies. 相似文献
3.
《Plant Production Science》2013,16(5):553-562
AbstractThe difference in rooting pattern between two grain sorghum cultivars differing in drought tolerance was investigated under drought stress. The cultivars, Gadambalia (drought-tolerant) and Tabat (droughtsusceptible), were grown in bottomless wooden or acrylic root boxes to examine root parameters. Gadambalia consistently exhibited higher dry matter production and leaf water potential than Tabat under drought stress in both root boxes. In the experiment with wooden root boxes, under a drought condition, Gadambalia extracted more water from deep soil layers (1.1-1.5 m), which was estimated from the reduction in soil water content, than Tabat. This was because Gadambalia had a significantly higher root length density in these soil layers. The high root length density was due to enhanced lateral root development in Gadambalia. In the other experiment with acrylic root boxes, though total root length in the upper soil layer (0-0.5 m) was declined by limited irrigation in both cultivars, the reduction in Gadambalia was moderate compared with that in Tabat owing to the maintenance of fine root growth. Unlike Tabat, Gadambalia had an ability to produce the nodal roots from higher internodes even under drought, which resulted in the high nodal root length of Gadambalia. The growth angle of nodal roots was significantly correlated with root diameter, and the nodal roots from the higher internodes had large diameters and penetrated into the soil more vertically. These results indicate that the responses of roots (i.e. branching and/or growth of lateral root, and nodal root emergence from higher internodes) to soil dryness could be associated with the drought tolerance of Gadambalia. 相似文献
4.
In this study, to identify deep rooting accessions, we assessed the differences in root depth based on the length of the longest primary root among 586 different rice accessions: 511 Oryza sativa and 75 O. glaberrima. Malagkit Pirurutong and Binicol were identified as the two rice accessions with deepest roots through four field experiments conducted at two different locations in West Africa. For these two accessions, root depths reached 35.6 and 41.4 cm, respectively, in the first experiment at Bamako; on the other hand, their depths only reached 22.6 and 18.6 cm, respectively, in the second and third experiments at Ibadan, leading to inconsistent genotypic ranking based on root depth between the two locations. However, Malagkit Pirurutong was identified as deep rooting in both locations; in addition, it showed deep rooting in the fourth experiment in a 20-mm irrigation treatment, even when compared with the deep rooting reference Azucena. Nonetheless, this pattern was not found under a 10-mm irrigation treatment. Malagkit Pirurutong kept developing deep roots even following 60 days after sowing (DAS), whereas other shallower rooting accessions ceased deepening by 60 DAS. The longer period for deepening roots would be beneficial for terminal drought stress. 相似文献
5.
《Plant Production Science》2013,16(3):164-173
AbstractMorphological adaptation of roots is critical for plants to survive under waterlogging. In this study, we evaluated the capacity of wheat to form aerenchyma in seminal roots in combination with the growth angle of the roots. We used five Japanese cultivars from the waterlogging-prone Kanto-Kyushu region in Japan, and a non-Japanese cultivar, Bobwhite for comparison. Seedlings in pot culture were waterlogged at a 3-cm depth for 7 days. The first adverse effect of waterlogging on plant growth was a significant reduction of root dry mass. The reduction rate varied with the cultivar, and it was 19.2% in cv. Shiroganekomugi and 40.0% in cv. Norin 61. Root aerenchyma was initially observed on the 2nd day of waterlogging and developed until the 7th day, in all 6 cultivars. Quantitative analysis of the aerenchyma development revealed no significant difference in radial distribution among the cultivars, whereas a slight difference was found in the axial distribution. As a consequence, the heavier root weight of Shiroganekomugi was not related to either the radial or axial developing capacity of aerenchyma but might be due to the effect of its shallow root angle in the soil. These results suggest that the capacity to form aerenchyma in the seminal root is not sufficient for expression of waterlogging tolerance in the Japanese wheat cultivars. 相似文献
6.
《Plant Production Science》2013,16(4):487-497
Root growth into deep soil is an important factor for stable production in wheat under drought conditions. Root penetrating capacity (RP) shown by pot experiments with a paraffin-Vaseline layer (PV layer) may be a useful indicator estimating deep rooting ability of wheat genotypes. Previously, we identified genotypes of durum wheat (Triticum turgidum L. var. durum) and bread wheat (T. aestivum L.) with diverse RP by the pot experiments. In this study, we investigated the root distribution of three Ethiopian landraces of durum wheat with high RP, three recent cultivars of durum wheat with low RP and one Japanese cultivar of bread wheat ‘Haruyutaka’ with low RP using: (1) pots with a PV layer, (2) root boxes, (3) artificial field and (4) a normal field to analyze the relationship between RP estimated by pot experiment and root development in the field. In the pot experiments, RP was evaluated by the number of roots penetrating through the PV layer (NRP). In the root-box and field experiments, the root distribution was evaluated by the number of roots on the vertical surface of soil as the root frequency (RF: root number cm-1 soil surface). Ethiopian landraces had a significantly larger NRP than recent cultivars in the pot experiment. The root box and field experiments showed that Ethiopian landraces tended to have a higher RF than recent cultivars in deep soil layer. We concluded that RP estimated by pot experiments with a PV layer is a useful indicator of deep rooting ability under field conditions. 相似文献
7.
小麦品种抗旱性与深根性和深层根系活性的关系 总被引：3，自引：0，他引：3
为明确小麦根系垂直生长与抗旱能力的关系,以不同抗旱类型品种洛旱6号、西农979和郑麦366为材料,在柱栽条件下研究了不同生育时期最大根深、根干重垂直分布、根系活性垂直变化等性状。结果表明,本试验条件下,小麦根深在挑旗期达最大值,越冬至挑旗期间根系生长速度快。挑旗期和抽穗期不同抗旱类型品种间根深差异显著,其中抗旱性强的品种最大根深较大;与抗旱性弱的品种相比,抗旱性强的品种总根干重和深层根干重小,根系生理活性强。籽粒灌浆期表现为抗旱性越强,深层根系生理活性越强。据此认为,抗旱性强的小麦品种未必具有较大的根干重或深层根干重,但其根系下扎深且深层根系生理活性较强,尤其是生育后期的根系生理活性强。 相似文献
8.
为明确磷肥对小麦品质及根系发育的影响及调控,以强筋小麦郑麦9023、中筋小麦周麦18号、弱筋小麦郑麦004为材料,研究了3个磷肥水平对不同筋力型小麦子粒蛋白质含量和根系数量性状及生理生化特性的影响。结果表明,增施磷肥在不同程度上增加次生根数,提高根系活力,降低根中可溶性糖含量,但高磷并不利于根系生长。次生根数在子粒灌浆期达最高值,其中,郑麦004的单株次生根数和主茎次生根数较多。根系对TTC的还原强度在拔节期达到最大值,成熟期降到最低,其中,郑麦9023对TTC的还原强度较弱。根中可溶性糖含量在冬前达到最大值,其中,周麦18号的根中可溶性糖含量较高。施磷增加周麦18号和郑麦9023的子粒蛋白质含量,但降低郑麦004的子粒蛋白质含量。 相似文献
9.
为了解普通小麦与其近缘种和人工合成材料(八倍体小偃麦、小黑麦)根系性状的差异,时普通小麦、黑麦、野生一粒小麦、拟斯卑尔脱小麦、提莫菲维小麦、八倍体小偃麦、小黑麦和硬粒小麦根系主要性状进行比较分析.结果表明,近缘种、人工合成材料单株次生根数、根体积、根干重和根冠比在生育后期均显著大于普通小麦,根系活力和生育前期的根中可溶性糖含量也均显著高于普通小麦.近缘种和人工合成材料根中全氮含量整体上低于普通小麦.相关分析表明,根系一些主要性状与籽粒全氮含量相关显著或极显著.综合来看,近缘种、人工合成材料具有发根力强、根系活力高等优势,在小麦改良中具有重要利用价值. 相似文献
10.
施磷水平对小麦根系生理及籽粒蛋白质含量的影响 总被引：1，自引：0，他引：1
为明确磷肥对小麦品质及根系发育的调控效应,以强筋小麦品种郑麦9023、中筋小麦品种周麦18号、弱筋小麦品种郑麦004为材料,研究了3个磷肥水平（0、90、180 kg P2O5·hm-2）对不同筋力型小麦籽粒蛋白质含量和根系数量性状及生理生化特性的影响。结果表明,施磷在不同程度上增加了小麦次生根数,提高了根系活力,降低了根系可溶性糖含量,但高磷（180 kg P2O5·hm-2）并不利于根系生长。3个小麦品种次生根数在籽粒灌浆期均达最高值,其中,郑麦004的单株次生根数和主茎次生根数较多;根系活力在拔节期达到最大值,成熟期降到最低,其中,郑麦9023根系活力较弱;根系可溶性糖含量在冬前达到最大值,其中,周麦18号的根系可溶性糖含量较高。施磷可增加周麦18号和郑麦9023的籽粒蛋白质含量,但降低郑麦004的籽粒蛋白质含量;在中磷（90 kg P2O5·hm-2）条件下,小麦蛋白质产量最高。综合考虑,在本试验条件下,以中磷处理效应最佳。 相似文献
11.
为了解冻害对不同基因型稻茬小麦苗期幼茎细胞结构的影响,选用皖麦50(半冬性品种)、皖麦48(弱春性品种)和郑麦9023(春性品种)为材料,在低温条件下连续用显微镜观测幼茎分蘖节薄壁细胞质壁分离变化情况。结果表明,在低温天气发生的初期,三个品种只发生了轻微的质壁分离,回暖后可恢复。当0℃以下低温持续10d以上时,质壁分离现象加重,皖麦48和郑麦9023分蘖节薄壁细胞原生质体出现不规则收缩,导管和筛管破裂,细胞失水收缩率最高达到30%左右,明显高于皖麦50。不同品种细胞失水收缩最大值均出现在连续低温之后,与最低温度出现时间不一致。 相似文献
12.
为解决油菜组织培养中组培苗生根细短、移栽不易成活的问题,以甘蓝型半冬性油菜转化pCAMBIA1301空载体的再生植株为材料,从生根时间、根长、根重、苗高、苗重、总重、生根数、生根率等方面,以MS和B5为基础培养基,分别使用琼脂糖、琼脂粉及植物凝胶为凝固剂时再生苗的生根效率,得到了两种基础培养基的最适凝固剂组合;在以上两种组合的培养基中分别加入不同浓度蔗糖,进一步比较生根情况和成本,认为含20 g/L蔗糖的B5琼脂粉培养基为最优配方。利用优化后的生根培养基配方,极大地促进油菜组培苗的生根长度和数目,提高后期移栽成活率。 相似文献
13.
《Plant Production Science》2013,16(3):335-343
AbstractDevelopmental plasticity in lateral roots may be one of the key traits for the growth of rice plants under soil moisture fluctuations. We aimed to examine responses in seminal root system development to changing soil moisture for diverse rice cultivars. Special attention was paid to the two different types of lateral roots ; the generally long, thick L type capable of branching into higher orders, and the non-branching S type. Plants were grown in half-split polyvinyl chloride tubes fixed with transparent acrylic plate for root observation under glasshouse conditions. When plants were grown first under drought conditions, then rewatered, the seminal root system development in terms of dry weight and total length was promoted as compared with plants grown under continuously well-watered conditions in IR AT 109 and Dular, drought tolerant cultivars. Promoted production of L type lateral roots mainly contributed to the development of the longer seminal root system. Plants exposed to soil submergence before they were grown under drought conditions did not show such promoted responses in these two cultivars. However, in KDML 105, a drought tolerant cultivar, the production of especially L type laterals was substantially promoted under drought and rewatered conditions. Honenwase was characterized by the shallow root system and great reduction in root system length when soil moisture becomes limited. These facts show that genotypic variations exist in the plastic response of rice seminal root system and that the L type lateral root plays a key role in manifestation of this plasticity. 相似文献
14.
Background
Root architectural and anatomical phenotypes are important for adaptation to drought. Many rice-growing regions face increasing water scarcity. This study describes drought responses of 11 Egyptian rice cultivars with emphasis on plastic root responses that may enhance drought adaptation.Results
Eleven Egyptian rice cultivars were phenotyped for root architectural and anatomical traits after 6 weeks growth in soil mesocosms under well-watered conditions. Four of these cultivars were more intensively phenotyped under progressive drought stress in mesocosms, using a system where more moisture was available at depth than near the surface. In response to drought stress, all cultivars significantly reduced nodal root number while increasing large lateral root branching density and total lateral root length in the deepest portions of the mesocosm, where moisture was available. Nodal root cross-sectional area, but not stele area, was reduced by drought stress, especially in the basal segments of the root, and the number of late metaxylem vessels was reduced in only one cultivar. Alterations in deposition of lignin were detected by UV illumination from laser ablation tomography, enhanced by digital staining, and confirmed with standard histochemical methods. In well-watered plants, the sclerenchyma and endodermis were heavily lignified, and lignin was also visible throughout the epidermis and cortex. Under drought stress, very little lignin was detected in the outer cell layers and none in the cortex of nodal roots, but lignin deposition was enhanced in the stele. Root anatomical phenes, including cross-section area and metaxylem vessel number and lignin deposition varied dramatically along large lateral root axes under drought stress, with increasing diameter and less lignification of the stele in successive samples taken from the base to the root apex.Conclusions
Root architectural and anatomical traits varied significantly among a set of Egyptian cultivars. Most traits were plastic, i.e. changed significantly with drought treatment, and, in many cases, plasticity was cultivar-dependent. These phenotypic alterations may function to enhance water uptake efficiency. Increased large lateral root branching in the deep soil should maintain water acquisition, while water transport during drought should be secured with a more extensively lignified stele.15.
Dinh Thi Ngoc Nguyen Roel Rodriguez Suralta Mana Kano-Nakata Shiro Mitsuya Stella Owusu-Nketia 《Plant Production Science》2018,21(2):93-105
Rainfed lowland rice fields are characterized by soil moisture fluctuations (SMF) and the presence of hardpan that impedes deep rooting and thus limits water extraction from deep soil layer during the periods of drought. In this study, we used rootboxes with three layers; shallow layer, artificial hardpan, and deep and wet layer below the hardpan, to evaluate differences in the plasticity of nodal roots elongation through the hardpan and promote root branching below the hardpan in response to SMF among four rice varieties; Sasanishiki, Habataki, Nipponbare, and Kasalath. Experiments were conducted during the summer and autumn seasons. Plasticity was computed as the difference in root traits within each variety between the SMF and continuously well-watered treatments. In both experiments, Habataki consistently tended to exhibit higher root plasticity than the other three varieties by increasing number of nodal roots that penetrated the hardpan during rewatering period in SMF, when the soil moisture increased and penetration resistance decreased. This root plasticity then contributed to greater water use at the deeper soil during the subsequent drought period and overall shoot dry matter production. Habataki had significantly higher δ13C value in roots at deep layer than roots at the shallow and hardpan layers under SMF, which may indicate that these were relatively newly grown roots as a consequence of root plasticity. This study also indicates that CSSLs derived from Sasanishiki and Habataki varieties may be suitable for the analysis of QTLs associated with root plasticity expression in rainfed lowland with hardpan and experiencing SMF. 相似文献
16.
Patterns of nodal rooting in Trifolium repens (L.) and correlations with stages in the development of axillary buds 总被引：1，自引：0，他引：1
Forty per cent of while clover nodes had roots when a pasture was rotationally grazed by sheep compared with 29% when grazed continuously by set stocking. Nodal roots were most frequent during spring and least frequent during summer. About 5% of nodes had a root primordium which had not developed but was still viable. A high proportion of nodal roots (66%) occurred within 10 nodes of the apex. Root presence was highly correlated with the establishment and survival of branches but was less closely related to branch initiation or the viability of axillary buds. It is suggested that the association between nodal roots and branches is strongest when resources are limited, and that root survival at a node is enhanced by the presence of a branch originating at the same node. 相似文献
17.
不同室内培养方法对玉米苗期根系生长的影响 总被引：1，自引：1，他引：0
采用溶液培养、石英砂培养和纸卷培养3种培养方法,在两个氮水平下研究不同基因型玉米的根系生长差异,比较不同培养方式对植株根系生长的影响。结果表明,不同的培养体系对植株生长性状影响较大,在相同的养分供应条件下,砂培的植株生物量、种子根长度、节根数、节根长度均显著超过纸培和水培。在实验期内(6叶期),砂培条件下氮素供应显著影响种子根总长度;在水培条件下,氮素显著影响节根数量及长度。因此,分析文献中的根系数据时要考虑培养条件,同时要根据实验目标来确定培养条件。 相似文献
18.
《Plant Production Science》2013,16(3):324-335
AbstractSoil water regimes under field conditions inevitably tend to fluctuate ranging from drought to waterlogging. Genotypes that adapt better to such changing hydrologic conditions are assumed to have the ability to maintain root system development under such conditions. This study aimed to evaluate the responses of root system development based on lateral root production to transient moisture stresses, and the contribution of the elongation of seminal and nodal root axes and their lateral, root branching, and aerenchyma development in the seminal root axis, to root system development. The seedlings of two aerobic genotypes (UPLRi7 and NSICRc9) and one irrigated-lowland genotype (PSBRc82), and two parental genotypes (Nipponbare and Kasalath) of chromosome segment substitution lines (CSSLs) were grown by hydroponics. The seedlings were exposed to a drought condition by adding polyethylene glycol to the solution for 7 days and then to an O2-deficient stagnant condition for 7 days (drought-to-stagnant condition), or to reverse successive conditions (stagnant-to-drought condition). Under both conditions, the aerobic genotypes showed greater ability to produce lateral roots than the irrigated-lowland genotype. Under the transient stagnant-to-drought condition, the root traits that contributed to greater lateral root production in the aerobic genotypes were faster seminal root elongation that was closely associated with branching of lateral roots, and greater nodal root production. Under transient drought to stagnant condition; these were faster seminal root elongation mediated by higher aerenchyma formation, and greater nodal root production. Kasalath showed much greater ability to produce lateral roots under both transient moisture stress conditions than Nipponbare. This indicates the potential utility of the CSSLs for precise identification of desirable root traits with less genetic confounding. 相似文献
19.
盐胁迫对小麦根系氧化损伤及细胞程序性死亡的影响 总被引：1，自引：0，他引：1
为探究小麦根系响应盐胁迫逆境的生理机制,以耐盐性不同的三个春小麦品种新春11号(高耐)、新春29号(中耐)和新春6号(盐敏感)为材料,分析300 mmol·L~(-1)NaCl胁迫对耐盐性不同的小麦品种根系生长、活性氧含量、抗氧化酶活性及细胞程序性死亡的影响。结果表明,与对照相比,盐胁迫下三个品种根长显著下降,根系干、鲜重均呈下降趋势,新春11号和新春29号变化幅度较小,而新春6号变化幅度相对较大;根尖中超氧阴离子产生速率保持增长趋势,耐盐性强的品种上升速率慢于耐盐性弱的品种,过氧化氢含量先增后降,最后与对照基本相同。超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性均在盐胁迫初期快速上升,胁迫30min后开始下降。SOD活性在耐盐性强的小麦品种中显著升高,而APX活性在耐盐性弱的品种中则显著升高。Evans Blue染色结果发现,随着盐胁迫时间的增加,死亡细胞数目逐渐增多。聚丙烯酰胺凝胶电泳显示,盐胁迫4h后即可检测到DNA片段化的发生,表明NaCl胁迫对小麦造成氧化损伤,诱导小麦根尖发生细胞程序性死亡。 相似文献
20.
《Plant Production Science》2013,16(4):286-287
AbstractThe growth directions and elongation rates of axile roots that compose the framework of an upland rice root system are quite varied. The objective of this study was to elucidate the direction of growth of the axile roots relative to their root diameter and the structural characteristics of their root caps. The relationships of photosynthate translocation to either the growth direction or the elongation rate of the axile roots were also examined using a stable isotope 13G. The growth direction of the axile roots significantly correlated with their diameter. The axile roots with a relatively large diameter tended to elongate vertically in the vegetative stage, though the regression coefficients varied according to phyllochrons. The roots that emerged at the reproductive stage elongated horizontally relative to the large diameter. In the roots that emerged at the same phyllochrons, the prophyll roots elongated more vertically than the proximal roots did. The axile roots that elongated vertically formed wide columellae and large amyloplasts in the cap cells. The highest 13C abundance in the axile root tip zone was found at 21 hrs after feeding 13CO2. The length of the apical unbranched zone behind the axile root tip positively correlated with the 13C abundance in the root apical zones during the first 21 hrs after feeding, indicating that the roots that elongated fast would be superior in photosynthate intake in the apical zone. The axile roots that elongated vertically took in more photosynthate in their apical zones, however, the relationship was not particularly close. 相似文献