首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
The present study is an attempt to prepare synthetic seeds using alginate encapsulation of nodal explants of Sterculia urens. Regeneration potential of encapsulated nodal segments was tested on MS basal, MS + BA (3.0 mg L?1), MS + TDZ (0.2 mg L?1), and MS + BA (0.5 mg L?1) + NAA (2.0 mg L?1). The regeneration potential was maximum (73.33 ± 1.33) on MS + TDZ (0.2 mg L?1) followed by (69.33 ± 1.76) on MS + BA (3 mg L?1) even after 6 months of storage at 4°C, whereas controls did not show any regeneration potential after 1 week. These findings suggest synthetic seed technology as an alternative method for micropropagation and germplasm conservation of Sterculia urens an endangered species.  相似文献   

2.
The effect of plant growth regulators and natural supplements on the morphogenetic response of Pogostemon cablin Benth. was investigated. Murashige and Skoog (MS) media supplemented with 0.5 mg L?1 benzyl-6-adenine and 0.5 mg L?1 kinetin was effective in inducing multiple shoots (63.20 ± 0.15) with an average shoot length of 5.27 ± 0.15 cm and biomass of 5.20 ± 0.10 g shoot?1. Among the natural supplements, 10% coconut water supplemented to MS media showed a better response in all the morphological parameters studied. The use of 10% tomato extract, 20% banana extract, 10% carrot extract, and 10% papaya extract in MS medium have efficiently increased multiple shoots, shoot length, and fresh weight of the shoots. The natural supplements also effectively increased the chlorophyll content, total protein, and total carbohydrate content in the plant. The frequency of rooting (93%) was highest when shoots were implanted on 1/2 strength MS media with 100 mg L?1 activated charcoal. The in vitro rooted plants were successfully acclimatized and established in soil. Also, RAPD analysis showed no variation suggesting true-to-type nature of the micropropagated plants. Hence, this protocol can effectively reduce the cost of in vitro multiplication of plants.  相似文献   

3.
Jatropha curcas, the energy plant has attained great attention in recent years because of its biodiesel production potential; however, oil and deoiled cakes are toxic. A non-toxic variety of J. curcas is reported from Mexico. A simple and efficient protocol has been developed for plant regeneration using cotyledonary petiole explants of non-toxic variety of J. curcas. The percentage of induction of shoot buds (59.11%), and the number of shoot buds (5.01) per explant was achieved on Murashige and Skoog’s (MS) medium supplemented with 2.27 μM thidiazuron (TDZ). These induced shoot buds multiplied when subcultured on MS medium supplemented with 10 μM kinetin (Kn), 4.5 μM 6-benzyl aminopurine (BAP), and 5.5 μM α-naphthaleneacetic acid (NAA) for 4 weeks and subsequent elongation achieved on MS medium supplemented with 2.25 μM BAP and 8.5 μM indole-3-acetic acid (IAA). Shoots more than 2 cm long were harvested and cultured on MS medium containing different concentrations and combinations of IBA, IAA, NAA, and 0.25 mg L?1 activated charcoal, and 19.91% rooting was achieved in 15 μM IBA, 5.7 μM IAA, and 16.5 μM NAA after 4 weeks with more than 90% survival rate.  相似文献   

4.
Kaempferia angustifolia is an aromatic, essential oil-yielding plant of the Zingiberaceae family with an ethno-medicinal repute. We standardized an effective system for micropropagation of K. angustifolia, and this is probably the very first report of in vitro culture of this species. Axillary buds were cultured on a Murashige and Skoog (MS) medium supplemented with various concentrations and combinations of plant growth regulators (PGRs) and spermidine. Highest multiplication occurred when the MS medium was supplemented with a combination of 2.0 mg L?1 6-benzylaminopurine (BAP), 2.0 mg L?1 kinetin (KIN) and 1.0 mg L?1 α-naphthalene acetic acid (NAA). Addition of spermidine (2.0 mM) along with optimum PGRs had further improved the multiplication rate with a maximum of 6.6 ± 0.36 shoots per explant within 60 days of implantation. The number of multiplied shoots per explant increased with each subsequent regeneration cycle; and the shoots per explant increased from 6.6 ± 0.36 on the 1st regeneration cycle to 10.3 ± 0.42 on the 2nd regeneration cycle and further increased to 13.7 ± 0.37 on the 3rd regeneration cycle on the same medium composition. The best result for in vitro root induction of multiplied shoot was achieved on a half-strength MS medium fortified with 2.0 mg L?1 IBA, with a maximum of 18.5 ± 0.28 roots per shoot. Regenerated plantlets were acclimatized with 88.9 % survival rate. After 9 months of field-transfer, all these plants were harvested and rhizomes were collected. However, the present protocol can definitely be applied for large-scale propagation and commercial cultivation of K. angustifolia.  相似文献   

5.
Mungbean (Vigna radiata) and rice bean (V. umbellata) (both species 2n = 2x = 22) have desirable traits that complement each other. In this study, we rescued embryos from a cross between mungbean cv. “Kamphaeng Saen 2” and rice bean cv. “Miyazaki” and resolved the hybrid sterility problem by colchicine treatment. The interspecific hybrids were obtained when Kamphaeng Saen 2 was used as the female parent. Four out of 80 immature seeds at 12 days old were able to germinate on an MS medium supplemented with 1 mg L?1 IAA, 0.2 mg L?1 kinetin, and 500 mg L?1 casein hydrolysate. Forty random amplified polymorphic DNA (RAPD) primers were screened for polymorphism among the parents, and two specific primers were finally chosen for testing of hybridity. Using the two primers, all putative F1 hybrids were confirmed as the interspecific hybrids. To observe their fertility, some of the hybrid seedlings were transplanted. The hybrid produced flowers profusely but failed to set pods. To overcome the sterility, plants were induced to become tetraploid by colchicine treatment in vitro. The ploidy level of the regenerated seedlings was confirmed from leaf DNA using a flow cytometer. Three out of 20 hybrid seedlings (15%) were successfully induced from diploid to tetraploid by a colchicine concentration of 2 g L?1. The tetraploid hybrids were able to produce flowers and set pods normally.  相似文献   

6.
This study was conducted to determine N topdressing rate at panicle initiation stage by using chlorophyll meter (SPAD-502)-based N nutritional diagnosis in rice plant for high quality production of the Chucheongbyeo variety. Field experiments were carried for 3 years from 2003 to 2005 in Gyeonggi, Hwaseong. To confirm the method of measuring the leaf color with SPAD-502, leaf position of rice plant and measuring point on the leaf were studied. And the proper period to examine the leaf color and growth characteristics of rice plants was suggested at panicle initiation stage, from the results of the correlation between SPAD value and both content of chlorophyll and nitrogen in rice leaves. The multiply value of plant height, number of tillers per m2 and SPAD value could explain well the effect of nitrogen fertilization on the growth of rice plants, and was used to determine an equation for on-site determination of nitrogen fertilization rate for Chucheongbyeo variety at the panicle initiation stage. Nitrogen fertilization increased number of tillers and rice yields, and affected the increase in protein content in rice grain resulting in loss of quality, such as taste value, and decreased the percentages of both ripened and whole rice grains. Based on the response surface statistical methodology using the SAS program, the relationship equation among protein content of brown rice (PROT), plant growth value (plant height × number of tillers × SPAD value, PGV), and nitrogen fertilization rate at the panicle formation stage (NF) was developed. That is, PROT (%) = 7.379403 ? (5.27E-7) a ? 0.013291 b + (3.025355E-13) a 2 + (3.222997E-8) ab + (6.781E-05) b 2, where a means PGV and b is NF (%), and the equation’s coefficient of determination (R2) was 0.967. From this equation, to recommend the optimum N fertilization rate at panicle initiation stage easily to produce high quality rice of Chucheongbyeo variety, which contains the target protein content of brown rice.  相似文献   

7.
This study was conducted to investigate cytotoxic effect, phenolic content, DPPH, ABTS radical scavenging rate and nitrite scavenging rate from different solvent fractions of Codonopsis lanceolate root. At all extracts concentration, the cytotoxic effect on different fractions against human cancer cells was higher in n-hexane and butyl alcohol fractions than in the other fractions. The IC50 value on HeLa cell showed the lowest by 62.70 μg.mL-1 on n-hexane fraction, and exhibited the values of butyl alcohol fraction 341.36 μg.mL-1, methylene chloride 598.33 μg.mL-1, ethyl acetate fraction 860.44 μg.mL-1, DW fraction 2896.82 μg.mL-1. Total polyphenol content on different solvent fractions varied from 102.43 to 153.52 mg.g-1, and that of ethyl acetate fraction showed the highest amount. The DPPH and ABTS radical scavenging activity showed that the increase was proportional to the concentration, and the scavenging activity also showed the highest in ethyl acetate fraction. The nitrite scavenging activity of each fraction at pH 1.2 was in the order of EA > BA > MC > n-H > DW, and the lower the acidity, the higher nitrite scavenging activity, and there was no distinct detection of nitrite scavenging effects of the pH range 6.0. The results of this study suggested that the extract of Codonopsis lanceolate root may assist in the potential biological activities, and it was found that the activity was different depending on the organic solvent fraction and the water fraction.  相似文献   

8.
The effect of coating brown rice with flour gel on the amount 2-acetyl-1-pyrroline (2AP) and n-hexanal was investigated. The brown rice was stored in different packaging and the quality of rice was monitored during storage. In all coating treatments, an inverse relationship was observed with the amount of 2AP decreasing as storage time increased. Coating brown rice has the effect of decreasing the amount of 2AP while obstructing the formation of n-hexanal. Vacuum packaging brown rice with laminated OPP/Al/LLDPE stabilizes both the amount of 2AP and n-hexanal. Color intensity of coated brown rice remained relatively unchanged during storage. Water activity of non-coated brown rice packed in OPP/Al/LLDPE was lowest.  相似文献   

9.
The role of phosphorus application on growth and yield of rice under saline conditions was studied in a set of two experiments, one in nutrient and the other in soil culture. In experiment 1, the effect of inorganic phosphate (Pi) on the growth and ionic relations of four rice cultivars, varying in salt tolerance and phosphorus use efficiency, grown in nutrient solution with and without 50 mol m?3 NaCl was measured in a 2 week trial. The growth of all rice cultivars was affected to different degrees due to external P, in the presence of salt. External P, concentration up to 100 μM in the presence of NaCl caused stimulation of all growth parameters (shoot, root, tillering capacity), above this concentration P, had an inhibitory effect. Salt-induced P toxicity was exhibited at a much lower P, concentration (10 μM) by the salt sensitive cultivar. Increasing the supply of phosphorus (from 1 to 100 μM Pi) to the saline medium tended to decrease the concentrations of Na1 and CI in all cultivars except IR 1561. Shoot concentrations of these saline ions were much lower in the salt tolerant and moderately salt tolerant rice cultivars. Shoot P and Zn concentrations showed an increasing trend in the presence of external P, and salt in the rooting nr -idium but most strikingly P: Zn ratio was lower in salt tolerant and moderately salt tolerant cultivars. Significantly higher concentrations of Na+, P and CI, and lower concentrations of Zn, were determined in the shoots of salt sensitive cultivars when exposed to salt stress in the presence of Pi Results were confirmed in naturally salt-affected soils of two different types (saline-sodic and saline) where paddy yield of NIAB 6 (salt tolerant) and IR 1561 (salt sensitive) showed improvement through moderate phosphorus supply (18 kg P ha?1).  相似文献   

10.
The present study describes the procedure for micropropagation of Dracocephalum kotschyi L. using shoot tips from in vitro-germinated plants. The best response was observed for shoot tips on MS medium containing 5 mg 6-benzylaminopurine L?1 and 0.2 mg 1-naphthaleneacetic L?1 acid. Regeneration for other types of the explant hypocotyls and cotyledons did not show satisfactory results so that the explants did not develop into normal shoots and in turn developed into the calli after 12 days of culture. Histochemical analysis showed that only the shoot tip revealed a direct induction of more teratological protuberances that arise around the cut end of the explants. Elongation of shoot buds was obtained on MS medium containing 1 mg BAP L?1 + 0.5 mg IBA L?1. Regenerated shoots rooted best on the same medium of elongation. After hardening, the rooted plants were transferred to the greenhouse where they grew, matured, and flowered normally with a survival rate of 95%. We concluded that the present protocol can be efficiently used for mass propagation of Dracocephalum kotschyi.  相似文献   

11.
Worldwide rice productivity is being threatened by increased endeavours of drought stress. Among the visible symptoms of drought stress, hampered water relations and disrupted cellular membrane functions are the most important. Exogenous use of polyamines (PAs), salicylic acid (SA), brassinosteroids (BRs), glycinebetaine (GB) and nitrous oxide (NO) can induce abiotic stresses tolerance in many crops. In this time course study, we appraised the comparative role of all these substances to improve the drought tolerance in rice (Oryza sativa L.) cultivar Super‐Basmati. Plants were subjected to drought stress at four leaf stage (4 weeks after emergence) by maintaining soil moisture at 50 % of field capacity. Pre‐optimized concentrations of GB (150 mg l?1), SA (100 mg l?1), NO (100 μmol l?1 sodium nitroprusside as NO donor), BR (0.01 μm 24‐epibrassinolide) and spermine (Spm; 10 μm ) were foliar sprayed at five‐leaf stage (5 weeks after emergence). There were two controls both receiving no foliar spray, viz. well watered (CK1) and drought stressed (CK2). There was substantial reduction in allometric response of rice, gas exchange and water relation attributes by drought stress. While drought stress enhanced the H2O2, malondialdehyde (MDA) and relative membrane permeability, foliar spray of all the chemicals improved growth possibly because of the improved carbon assimilation, enhanced synthesis of metabolites and maintenance of tissue water status. Simultaneous reduction in H2O2 and MDA production was also noted in the plants treated with these substances. Drought tolerance was sturdily associated with the greater tissue water potential, increased synthesis of metabolites and enhanced capacity of antioxidant system. Of all the chemicals, foliar spray with Spm was the most effective followed by BR.  相似文献   

12.
This study was executed to evaluate the phenolic content, DPPH, ABTS radical scavenging rate, nitrite scavenging rate, and anti-inflammatory activity from in vitro cultured adventitious root extract of different Platycodon grandiflorum(PG) variety. Total polyphenol and flavonoid content showed the highest amount in adventitious root extract of tetraploid PG, and followed by green petal, double petal and diploid PG extract. The DPPH radical scavenging activity showed that the increase was proportional to the concentration, especially, the scavenging activity at a concentration of 10 mg mL-1 was higher than 80%. The ABTS radical scavenging activity was not significantly different among the PG varieties at the concentration of 5 mg mL-1 or more, and generally showed high scavenging activity. The nitrite scavenging activity was affected by pH, at pH of 1.2, the scavenging effect of all of the extracts tested observed higher than that of the other two pH ranges. The cytotoxicity of PG extract at various concentrations, the survival rate of RAW 264.7 cell was more than 90% at a concentration of 200 μg mL-1 or less, and it was confirmed that the macrophage cell showed little toxicity. After PG extract pretreatment at 50, 100, and 200 μg mL-1, LPS-treated experimental group significantly inhibited NO production in a dose-dependent manner. The dose-response trends followed quadratic regressions in all PG varieties. The PG extracts showed a considerable range of influence on cytokine secretion. The effect of adventitious root extracts of PG against inflammatory mediators TNF-α, IL-6 and IL-1β production showed the most significant anti-inflammatory activity.  相似文献   

13.
Anthers of Brassica nigra, excised from fresh as well as cold-pretreated (3 days at 3 ± 2°C) buds cultivated on modified B5 medium (Gamborg et al. 1968) containing sucrose level varying from 2 % to 10 %, along with 1O?6M BAP (benzylaminopurine) and 9 × 10?6M 2,4-D (2,4-dichlorophenoxyacetic acid), developed calli and/or embryos. The latter response was observed only in anthers reared on media containing 6 % or higher levels of sucrose. On media containing two or four per cent sucrose, the anthers produced calli, exclusively. The growth of embryos was inhibited or else they started callusing if left on the media containing higher levels of sucrose. However, on transfer to MS medium (Murashige and Skoog 1962), containing 2 % sucrose, embryos started callusing and subsequently a few secondary embryos differentiated. Such embryos were sub-cultured on MS + 5 × 10?6M BAP + 2 % sucrose, wherein numerous shoots developed from embryos. The shoots were rooted by transferring to a medium containing 5 × 10?6M NAA (naphthalene acetic acid). Within two months of culture, some of these plants started flowering in vitro.  相似文献   

14.
Sheath lesions, grain sterility and grain discolouration of rice caused by Pseudomonas fuscovaginae can cause yield losses of up to 100 %. The most sustainable method of managing this disease is the use of host plant resistance. To identify sources of resistance an inoculation method that is practical, rapid and reliable is needed. We compare three different inoculation methods. Results showed that the pin-prick method is appropriate for identifying sources of resistance to P. fuscovaginae, while the spray method could be useful for mass screening of rice genotypes. The seed-soaking method was also evaluated and has showed potential in detection of early disease resistance. A total of 16 Multiparent Advanced Generation Inter-Crosses and 20 OryzaSNP set varieties from the International Rice Research Institute were evaluated using the pin-prick and seed-soaking methods. All growth stages were susceptible to the pathogen and the 107 cfu mL?1 inoculum concentration was optimal for discriminating between resistant and susceptible genotypes. For the pin-prick method, a single point assessment of disease severity at 14 days post-inoculation could be used instead of the AUDPC values to classify genotypes. An index of reduction in seedling height 10 days after seed soaking was established for the classification of the genotypes reaction to the disease. Resistant varieties identified using both the pin-prick and seed-soaking methods could be verified for use in disease resistance breeding programs. Of the 36 genotypes evaluated 22 were found to be resistant at the late booting or early panicle exsertion stage by pin-prick method, while 25 were resistant at the seed to germination stage. No correlation was found between the resistance classification of varieties between the two inoculation methods, indicating that there could be different mechanisms of resistance to P. fuscovaginae in rice.  相似文献   

15.
钙对水稻苗期光合特性影响及其亚细胞分布   总被引：1，自引：0，他引：1  
为了探明钙对水稻苗期光合特性影响及其在亚细胞分布的分布规律,选用高糙米钙含量品种和低糙米钙含量品种为试验材料,采用水培方法研究了钙对水稻苗期光合特性的影响及其在水稻不同类型品种中的亚细胞分布。结果表明,高钙品种的叶片净光合速率明显强于低钙品种。水稻叶片中钙含量大于根系中钙含量。在各重要细胞器组分中,钙分布表现为细胞壁>核糖体及细胞内可溶物>质体（或叶绿体）>线粒体>细胞核,细胞壁是钙最主要分布场所,细胞核﹑线粒体中分布较少。各细胞器中钙含量随钙处理浓度升高而增加,高钙品种表现更为明显。高钙处理对高钙品种各重要细胞器钙增加明显,推测高钙品种表现出更强的积累钙和耐受高钙胁迫能力。  相似文献   

16.
An experiment was carried out to determine the plant growth-promoting activities of fipronil- and pyriproxyfen-tolerant Mesorhizobium isolates in the presence and absence of insecticides. The bioremediation and plant growth-promoting potentials of Mesorhizobium isolate (MRC4) was assessed using chickpea as a test crop grown under fipronil- and pyriproxyfen-stressed soils. In this study, the most promising mesorhizobial isolate (MRC4) tolerated fipronil and pyriproxyfen up to a concentration of 1600 μg ml?1 and 1400 μg ml?1, respectively. Isolate MRC4 produced a substantial amount of indole acetic acid (44.3 μg ml?1), salicylic acid (35 μg ml?1), 2,3 di-hydroxybenzoic acid (19 μg ml?1), and exo-polysaccharides (21 μg ml?1) in the absence of insecticides. The plant growth-promoting substances displayed by the isolate MRC4 declined progressively with increasing concentrations of each insecticide. The insecticide tolerant isolate MRC4 was further tested for its effect on chickpea plants grown in fipronil- and pyriproxyfen-treated soils. The insecticide-tolerant isolate MRC4 increased the dry matter accumulation progressively. A maximum increase of 80 (at 600 μg kg?1 soil of fipronil) and 118% (at 3900 μg kg?1 soil of pyriproxyfen) was recorded 135 days after sowing when compared to noninoculated plants treated with the same rates of each insecticide. Moreover, Mesorhizobium isolate MRC4 when used in fipronil- and pyriproxyfen-treated soil also increased symbiotic properties (nodulation and leghaemoglobin content), root N, shoot N, root P, shoot P, seed yield, and seed protein compared to the un-inoculated but treated solely with insecticide. The present finding suggests that the mesorhizobial isolate endowed with multiple properties could be used to facilitate the productivity of chickpea under insecticidestressed soils.  相似文献   

17.
Brown rot caused by Monilinia spp. is the most important postharvest disease of stone fruit. Currently, no chemical fungicides are allowed in the European Union to be applied to stone fruit after harvest. In previous work, radio frequency (RF) treatment for 4.5 min applied with fruit immersed in water at 40 °C was very promising for the control brown rot on peaches and nectarines. In the present study, the efficacy of this radio frequency treatment was studied employing different infection times, inoculum concentrations, fruit maturity levels and in naturally infected fruit. Generally, infection time and maturity level of fruit did not have a significant effect on the RF treatment efficacy and brown rot incidence was significantly reduced in fruit inoculated 0, 24 or 48 h before treatment and at all maturity levels evaluated in both peaches and nectarines. RF treatment significantly reduced brown rot incidence at all inoculum concentrations evaluated (103, 104, 105 and 106 conidia mL−1). However, in peaches, the treatment efficacy was slightly less when the inoculum concentration was increased to 105 or 106 conidia mL−1. In naturally infected fruit, brown rot incidence was significantly reduced from 92% among control fruit to less than 26% in peaches and complete brown rot control was achieved in nectarines. RF treatment did not have an effect on fruit firmness in the varieties tested, and even a delay of fruit softening was observed. Moreover, both external and internal fruit appearance was not affected by the treatment.  相似文献   

18.
The gall wasp Leptocybe invasa is a major insect pest on plantation Eucalyptus in many countries. Since appearing in China in 2007 it has had major impacts on commercial plantations—some commonly planted Eucalyptus varieties have proven particularly susceptible, including hybrids involving Eucalyptus camaldulensis and E. tereticornis parent species. Intra-specific variation within each species for L. invasa susceptibility was examined in two seed source and family trials in southwest of Guangdong. The E. camaldulensis trial included 101 seedlots representing five natural stand and six seed orchard sources which also represented three sub-specific taxa. The E. tereticornis trial included 143 seedlots representing 11 natural stand and four seed orchard sources, including breeding seed orchards in China. Both trials were assessed for susceptibility to L. invasa along with height at age 9 months. Sub-specific taxa within E. camaldulensis differed significantly (P < 0.01) in L. invasa susceptibility but not height or survival; subsp. acuta had the lowest average susceptibility and subsp. simulata and obtusa were of intermediate susceptibility whilst material of uncertain sub-specific taxa from India had the highest average susceptibility. In E. tereticornis regions of origin and seed sources within regions differed significantly (P < 0.01) for both L. invasa susceptibility and height; the region China (all somewhat improved sources) had both the best average height growth and lowest susceptibility whilst the region Australia (all natural stand sources) proved inferior to China for both average susceptibility and height. A strong significant correlation was found between seed source average L. invasa susceptibility and annual rainfall at seed source geographic origin in E. tereticornis (r = ?0.873; P < 0.01), implying that seedlots from higher rainfall environments are markedly less susceptible to L. invasa. The equivalent parameter in E. camaldulensis was also strong (r = ?0.730) though not significant, perhaps due to having only five data points available. Differences between families within seed sources for both L. invasa susceptibility and height growth were also highly significant (P < 0.01) with the former trait proving moderately to strongly heritable (h i 2  = 0.54 ± 0.40 in E. camaldulensis; 0.52 ± 0.50 in E. tereticornis). Height had low to moderate heritability in both species (h i 2  = 0.11 ± 0.15 and 0.26 ± 0.08 respectively). Tree height and L. invasa susceptibility showed a moderate negative (favourable) genetic correlation in E. camaldulensis (?0.33 ± 0.64) and a moderate to strong negative (favourable) genetic correlation in E. tereticornis (?0.47 ± 0.31). Corresponding phenotypic correlations, though significant, were somewhat weaker (?0.16 and ?0.29 respectively), indicating a trend for taller trees to have lower levels of L. invasa susceptibility.  相似文献   

19.
Brown rot caused by Monilinia spp. is the most important postharvest disease of stone fruit. From preliminary studies, the combination of 0.25% hydrogen peroxide, 0.02% peracetic acid (PAA) and 0.075% acetic acid, corresponding to 300 mg L−1 of PAA, was selected to control Monilinia fructicola. Brown rot control was similarly controlled when the same concentration of PAA was applied with a PAA-based commercial product. In order to reduce PAA concentration, combinations of different concentrations and temperatures were evaluated. A treatment of 200 mg L−1 of PAA at 40 °C for 40 s was selected to control pre-existing and future infections, different inoculum concentrations of M. fructicola and to control brown rot on naturally infected fruit. Brown rot was completely controlled with the selected treatment when peaches and nectarines were inoculated 0 h before the treatment but it was not controlled when infection time was increased to 24, 48 and 72 h. Also, the treatment significantly controlled brown rot at all inoculum concentrations evaluated (103, 104, 105 and 106 conidia mL−1) in both peaches and nectarines, but no protection against future infections was observed. In naturally infected fruit, brown rot incidence was slightly but significantly reduced to 61 and 36% in ‘Roig d’Albesa’ and ‘Placido’ peaches, respectively, but not in nectarines. Immersion for 40 s in 200 mg L−1 of PAA at 40 °C provides an alternative treatment to control only recent infections of Monilinia spp. whatever their concentration without generally affecting fruit quality.  相似文献   

20.
蓝伟侦  柳哲胜  李刚  覃瑞 《作物学报》2007,33(4):560-565
用覆盖抗褐飞虱基因Bph15的两个BAC克隆，即20M14 (27 kb)和64O9 (36 kb)作为探针，对非洲栽培稻、药用野生稻和宽叶野生稻体细胞染色体进行荧光原位杂交(FISH)。两个BAC克隆均被定位于非洲栽培稻和药用野生稻第4染色体的短臂上，杂交信号的百分距离分别为37.03±4.11和81.22±3.62，相应的信号检出率为41.18%和38.22%。在宽叶野生稻中，有两对同源染色体同时检出信号，分别定位于染色体的短臂和着丝粒区，信号距着丝粒平均百分距离分别为87.78±5.23和0，信号检出率为52.58%。由此推知，这两个BAC克隆在非洲栽培稻和药用野生稻的第4染色体分布同线且同区，并且在宽叶野生稻的DD基因组也存在Bph15基因的同源序列。在未封阻的情况下，BAC克隆在非洲栽培稻的多条染色体上有杂交信号，表明它和栽培稻C0t-1 DNA在一定程度上具有同源性。上述结果初步显示Bph15在3个稻种染色体中的相对位置。文章讨论了Bph15在3个种间的关系，为有效分离和利用Bph15基因提供了有益的依据，对不同基因组及二倍体和四倍体中功能基因可能进化机制的分析提供了线索。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号