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1.
This paper presents evidence from an initial trial in favor of claims that the liquid seaweed extract of Ascophyllum nodosum, marketed in the UK as Maxicrop, can reduce numbers of the two-spotted red spider mite Tetranychus urticae on crop plants. Seven applications of Maxicrop Triple over 20 days significantly suppressed the population build-up of two-spotted red spider mites on treated strawberry plants (Fragaria sp. var. Redgauntlet) raised under high polythene tunnels as compared to untreated controls. 相似文献
2.
Effects of NaCl stress on germination, antioxidant responses, and proline content in two rice cultivars 总被引:1,自引:0,他引:1
Young Geol Sohn Byung Hyun Lee Kyu Young Kang Jeung Joo Lee 《Journal of Plant Biology》2005,48(2):201-208
We investigated the physiological and biochemical bases for salt tolerance in two rice (Oryza sativa L.) cultivars — relatively salt-tolerant ‘Dongjin’ and salt-sensitive ‘Kumnam’. Salinized hydroponic cultures were studied
at the germination and seedling stages. NaCI inhibited germination more severely in ‘Kumnam’ than in ‘Dongjin’. Increasing
the salt concentration also deterred growth to a larger extent in the former. Moreover, the leaves of ‘Kumnam’ exhibited greater
increases in lipid peroxidation and Na+ accumulation than those of ‘Dongjin’ under stress. The activities of constitutive and salt-induced superoxide dismutase (SOD,
EC 1.15.1.1) and ascorbate peroxidase (AP, EC 1.11.1.11) were also higher in ‘Kumnam’, while only catalase (CAT, EC 1.11.1.6)
activity was slightly higher in stressed plants of ‘Dongjin’. The positive correlation between leaf proline levels and NaCI
concentration was more evident in ‘Kumnam’. However, ‘Dongjin’ seeds, which had higher germinability in the presence of NaCI,
also contained more proline. These results suggest that the higher salt tolerance in ‘Dongjin’ seedlings could be ascribed
to their lower NaCI accumulations in the leaves. This presumably is due to reductions in the uptake or transport rates of
saline ions to the shoots from the roots. Finally, we believe that the higher germination rate by ‘Dongjin’ is caused by its
higher seed proline content. 相似文献
3.
A. Q. Hurtado A. T. Critchley A. Trespoey G. Bleicher Lhonneur 《Journal of applied phycology》2006,18(3-5):301-306
This paper describes the occurrence of an epiphyte infestation of Kappaphycus farms in Calaguas Is. Camarines Norte, Philippines. In particular, percentage cover of ‘goose bump’-Polysiphonia and ‘ice-ice’ disease, and some environmental parameters that influence the thallus condition of Kappaphycus
alvarezii in Calaguas Is. were assessed during 3 separate visits and are discussed.Commercial cultivation of Kappaphycus at Calaguas Is. began in the early 1990s. After five years of farming, the stock was destroyed by a strong typhoon. The area was re-planted the following year and production increased annually and reached its peak in 1998–1999. However, the following year, the first occurrence of a Polysiphonia epiphyte infestation occurred concurrently with an ‘ice-ice’ disease. Consequently, annual production and the number of seaweed planters declined rapidly, and this situation persists to the present time. This paper highlights the etiological factors and their consequences.Results show that farm-site selection is critical for the success of Kappaphycus production. Characteristics of water movement and light intensity in farming areas contributed to the occurrence and detrimental effect of the phenomenon described as ‘goose bumps’: a morphological distortion of the host seaweed due to the presence of a Polysiphonia sp. epiphyte. A strong inverse correlation was observed between the occurrence of Polysiphonia and water movement: areas with low water motion registered a higher % cover (65%) of Polysiphonia than those in more exposed areas (17%). Although ‘goose bump’-Polysiphonia infestation and ‘ice-ice’ disease pose a tremendous problem to the seaweed farmers, the results of this limited assessment provide a useful baseline for future work. 相似文献
4.
Response of strawberry to inoculation with arbuscular mycorrhizal fungi under very high soil phosphorus conditions 总被引:1,自引:0,他引:1
A field study was done to assess the potential benefit of arbuscular mycorrhizal (AM) inoculation of elite strawberry plants
on plant multiplication, under typical strawberry nursery conditions and, in particular, high soil P fertility (Mehlich-3
extractible P=498 mg kg−1). Commercially in vitro propagated elite plants of five cultivars (‘Chambly,’ ‘Glooscap,’ ‘Joliette,’ ‘Kent,’ and ‘Sweet
Charlie’) were transplanted in noninoculated growth substrate or in substrate inoculated with Glomus intraradices or with a mixture of species (G. intraradices, Glomus mosseae, and Glomus etunicatum) at the acclimation stage and were grown for 6 weeks before transplantation in the field. We found that AM fungi can impact
on plant productivity in a soil classified as excessively rich in P. Inoculated mother plants produced about 25% fewer daughter
plants than the control in Chambly (P=0.03), and Glooscap produced about 50% more (P=0.008) daughter plants when inoculated with G. intraradices, while the productivity of other cultivars was not significantly decreased. Daughter plant shoot mass was not affected by
treatments, but their roots had lower, higher, or similar mass, depending on the cultivar–inoculum combination. Root mass
was unrelated to plant number. The average level of AM colonization of daughter plants produced by noninoculated mother plants
did not exceed 2%, whereas plants produced from inoculated mothers had over 10% of their root length colonized 7 weeks after
transplantation of mother plants and ∼6% after 14 weeks (harvest), suggesting that the AM fungi brought into the field by
inoculated mother plants had established and spread up to the daughter plants. The host or nonhost nature of the crop species
preceding strawberry plant production (barley or buckwheat) had no effect on soil mycorrhizal potential, on mother plant productivity,
or on daughter plant mycorrhizal development. Thus, in soil excessively rich in P, inoculation may be the only option for
management of the symbiosis. 相似文献
5.
Ecklonia maxima is an economically important kelp in South Africa. The harvested kelp is used mainly as feed for cultured Haliotis midae (abalone) on farms all along the South African South and West Coast. The effects that different harvesting methods have on the growth of sub-canopy kelps, kelp population structure and kelp recruitment were tested in a kelp bed at Bordjies Rif near Cape Town. Two 30 × 10 m sites were set up, about 100 m apart, in near monoculture stands of E. maxima. Each 30×10 m area was subdivided into three treatments. In treatment 1 (T1) the whole ‘head’ of each kelp sporophyte that reached the surface was cut off between the bulb and the primary blade (‘lethal’ method). In treatment 2 (T2) (‘non-lethal’ method), the secondary fronds of all sporophytes that reached the surface were cut 20–30 cm from their junction with the primary blade, and removed. In the control plot, the kelp plants were not treated. Harvesting treatments were done approximately every four months, at low spring tide, from 3 March 2003 to 3 November 2003 (three treatments). The effects of harvesting on the kelps depend largely on the size of plant and the time the fronds were removed; however, no seasonal pattern could be observed. The different treatments had no effect on the growth rate, population structure or recruitment of the kelp. This means that factors other than light play an important role in the growth, structure and recruitment of the kelp beds in False Bay. Results are discussed in relation to current commercial harvesting practices. 相似文献
6.
J. G. Roddick G. Melchers 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1985,70(6):655-660
Summary Analyses of leaves and ‘tubers’ from somatic hybrids of potato and tomato (‘pomato’ with plastids of potato, ‘topato’ with
plastids of tomato) produced by fusion of protoplasts from liquid cultures of dihaploid potato and mesophyll of tomato revealed
the presence of the two major potato glycoalkaloids (α-solanine and α-chaconine) as well as the tomato glycoalkaloid (αtomatine). The total alkaloid content of leaves was greater than that of ‘tubers’ and similar to levels in the foliage of
parent plants. However, glycoalkaloids were more abundant in hybrid ‘tubers’ than in normal potato tubers by a factor of 5–15.
In hybrid foliage, approximately 98% of the alkaloid present was of potato origin whereas in ‘tubers’ the reverse was the
case, with tomatine comprising 60–70% of the total alkaloid. The similarities in alkaloid content and ratios between the pomato
and the topato lines indicate that plastomes do not influence the biosynthesis and distribution of these alkaloids. The results
indicate that major secondary metabolites may prove useful for assessing the hybrid nature of such plants. 相似文献
7.
8.
C. Douglas Boyette Mark A. Jackson Charles T. Bryson Robert E. Hoagland William J. ConnickJr. Donald J. Daigle 《BioControl》2007,52(3):413-426
The weed Sesbania exaltata (Raf.) Rydb. ex A.W. Hill (hemp sesbania) was effectively controlled in soybean [Glycine max (L.) Merr.] field test plots over a 2-year testing period (1995–1996) with microsclerotia of the bioherbicidal fungus, Colletotrichum truncatum, formulated in wheat gluten-kaolin granules called ‘Pesta’. Weed control averaged 84% and 88%, respectively, in plots treated
pre-plant incorporated (PPI) at ‘Pesta’ rates of 168 or 336 kg ha−1, and 71% and 78%, respectively, in plots treated pre-emergence (PE) at ‘Pesta’ rates of 168 or 336 kg ha−1 over the testing period. Post-emergence (POE) control averaged 30% and 50%, respectively, for the 168 and 336 kg ha−1 treatments, and was significantly less effective than either PE or PPI treatments. Although pathogenesis and mortality occurred
in hemp sesbania tissues, satisfactory weed control was not achieved in plots treated at rates of 17 or 84 kg ha−1 with any of the application methods. Soybean yields were significantly greater in test plots treated PPI or PE, as compared
to yields from test plots treated either POE, with inert ‘Pesta’ granules, or from untreated controls. Microsclerotia formulated
in ‘Pesta’ granules exhibited excellent shelf-life, retaining high viability after storage for 10 years at 4 °C. These results
suggest that microsclerotia of C. truncatum formulated in ‘Pesta’ granules offers an effective method for controlling this important weed and preserving the activity
of this bioherbicide. 相似文献
9.
Effects of exogenous B supply on growth, B accumulation and distribution of two navel orange cultivars 总被引:3,自引:0,他引:3
Ou Sheng Shang W. Song Yun J. Chen Shu A. Peng Xiu X. Deng 《Trees - Structure and Function》2009,23(1):59-68
To investigate the effects of boron (B) on growth, B concentration and distribution of two navel orange cultivars, ‘Newhall’
(Citrus sinensis Osbeck) and ‘Skagg’s Bonanza’ (Citrus sinensis Osbeck) grafted on the rootstock trifoliate orange [Poncirus trifoliata (L.) Raf.], B at five levels was exogenously supplied to 1-year-old grafted plants of both cultivars under greenhouse conditions.
Plants were grown in sand:perlite (1:1, v/v) medium and were irrigated every 2 days with half-strength Hoagland’s No. 2 nutrient
solutions containing different B, 0.01, 0.05, 0.10, 0.25 and 2.50 mg l−1 (0.25 and 2.50 mg l−1 were considered as control and excess B treatment, respectively, and the other three B levels were considered as low B treatments).
After treatments for 183 days, leaves (from basal, middle, upper parts of the shoots), stem of scion, stem of rootstock and
root were separately sampled. Our results showed that plant growth (plant height, root volume and dry weights of various parts)
was inhibited in response to low or excess B supplies in both cultivars. It was found that B concentrations in the upper leaves
of both cultivars were substantially higher than those in the basal leaves when low concentrations (≤0.05 mg l−1) of exogenous B were applied, suggesting that B was preferentially translocated to the upper-younger leaves to support their
growth. Analysis of B distribution in different parts indicated that translocation of B from the root to the scion’s shoots
(stems and leaves of scion) may be restricted upon exposure to low B conditions. When B was inadequately supplied, growth
of ‘Skagg’s Bonanza’ was better than ‘Newhall’, implying that the former cultivar was more tolerant to low B status, which
may be due to the higher efficiency of B translocation from the root to the scion’s shoots. However, when the plants were
treated with excess B (2.50 mg l−1), both cultivars showed a similar degree of B toxicity. The probability of scion–rootstock interactions in relation to the
differential responses of growth and different efficiency of B translocation involved in the two orange cultivars following
the long-term low B stress were discussed. 相似文献
10.
Mitsuhiro Obara Wataru Tamura Takeshi Ebitani Masahiro Yano Tadashi Sato Tomoyuki Yamaya 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,121(3):535-547
Root system development is an important target for improving yield in cereal crops. Active root systems that can take up nutrients
more efficiently are essential for enhancing grain yield. In this study, we attempted to identify quantitative trait loci
(QTL) involved in root system development by measuring root length of rice seedlings grown in hydroponic culture. Reliable
growth conditions for estimating the root length were first established to renew nutrient solutions daily and supply NH4
+ as a single nitrogen source. Thirty-eight chromosome segment substitution lines derived from a cross between ‘Koshihikari’,
a japonica variety, and ‘Kasalath’, an indica variety, were used to detect QTL for seminal root length of seedlings grown in 5 or 500 μM NH4
+. Eight chromosomal regions were found to be involved in root elongation. Among them, the most effective QTL was detected
on a ‘Kasalath’ segment of SL-218, which was localized to the long-arm of chromosome 6. The ‘Kasalath’ allele at this QTL,
qRL6.1, greatly promoted root elongation under all NH4
+ concentrations tested. The genetic effect of this QTL was confirmed by analysis of the near-isogenic line (NIL) qRL6.1. The seminal root length of the NIL was 13.5–21.1% longer than that of ‘Koshihikari’ under different NH4
+ concentrations. Toward our goal of applying qRL6.1 in a molecular breeding program to enhance rice yield, a candidate genomic region of qRL6.1 was delimited within a 337 kb region in the ‘Nipponbare’ genome by means of progeny testing of F2 plants/F3 lines derived from a cross between SL-218 and ‘Koshihikari’. 相似文献
11.
The effects of post harvest application of ethylene, abscisic acid (ABA), indole-3-butyric acid (IBA) treatments or dark storage
on root induction and continued growth of regenerated roots in Pelargonium cuttings were investigated using hydroponics in the greenhouse. Ethylene markedly increased rooting percentage in ‘Greco’
and ‘Surfing’, reduced the number of roots per cutting in ‘Surfing’ and had no effect on the total root lengths in the two
cultivars. Ethylene treatment reduced fresh root mass in ‘Surfing’, increased dry root mass and reduced root water content
in both cultivars. ABA (50 μM) enhanced rooting percentage in ‘Greco’, reduced the number of roots per cutting, reduced total
root lengths and fresh root mass in both cultivars. ABA increased dry root mass and reduced root water content in ‘Surfing’
but this effect was not apparent in ‘Greco’. Storing cuttings in the dark for 4 days had no effect on rooting percentage and
number of roots per cutting in ‘Greco’ and ‘Surfing’. However, dark storage reduced total root lengths in ‘Surfing’ and reduced
fresh root mass in ‘Greco’. Dark storage had no effect on dry root mass and water content in both cultivars. Applying 4 μl l−1 IBA in the rooting solution induced maximum (100%) root induction in ‘Surfing’. However, IBA reduced the number of roots
per cutting in ‘Greco’, reduced total root lengths and fresh root mass in the two cultivars. IBA treatment profoundly increased
and reduced dry root mass and root water content, respectively, in ‘Greco’ and ‘Surfing’. The enhanced root induction observed
after IBA and ABA applications could be ascribed to their influence on ethylene biosynthesis, since ethylene treatment increased
rooting percentage in both cultivars. However, high ABA (100 μM) and IBA (12 μl l−1) levels or dark storage reduced the ability of induced roots to continue growth. We attribute our results to plant stress-response
mechanism and ethylene appears to play an important role in the process of root initiation and root growth in Pelargonium cuttings. 相似文献
12.
Summary Use of lysozyme was tested for treatment of bacterial contaminations in in vitro shoot cultures of quince (Cydonia oblonga) ‘BA 29’ and the hybrid (Prunus persica × P. amygdalus) rootstock ‘GF 677’. Shoots which had been contaminated for about 1 yr by Bacillus circulans and Sphingomonas paucimobilis were treated in liquid culture, at pH 4.5, with 9–36 mg ml−1 egg white lysozyme (EWL), and compared to each other and to untreated cultures for their growth, proliferation, and number
of bacterial colony-forming units in the tissues. EWL did not negatively affect shoot growth up to 18 mg ml−1; furthermore, the proliferation rates of EWL-treated shoots were sometimes higher than those of controls. In contrast, the
concentration of 36 mg ml−1 had some deleterious effect on the regrowth capacity and shoot production of ‘GF 677’ at the first subculture to solid medium
after EWL, treatments. EWL had a simple bacteriostatic effect against Sphingomonas paucimobilis; in contrast, it was effective at 18 mg ml−1 in eliminating Bacillus circulans in both ‘BA 29’ and ‘GF 677’ cultures, after optimal treatment duration. 相似文献
13.
14.
Summary Agitated layers of liquid medium were created on platform shakers in jars with 25–30 ml of medium (similar to conventional
agar culture) rotating at 90 rpm. Thin films were scaled up in larger rectangular vessels on tilted shelves that periodically
rock. In jars of liquid medium with a density of 180 explants per liter, multiplication rates of Hota tokudama var. ‘Newberry Gold’ were optimal with a media sucrose concentration of 5% [both with and without 1 μM benzyladenine (BA)]. Endogenous levels of soluble sugars were directly related to the concentration of sucrose in the medium.
Three Hosta cultivars (‘Striptease’, ‘Minuteman’, and ‘Stiletto’) with plant densities of 40–200 explants per liter of medium were tested
in larger, agitated, thin-film vessels in media with 5% sucrose and directly compared to agar medium. Higher rates of multiplication
were observed in liquid than agar with the magnitude of the difference dependent on explant density. Pooled results for the
three varieties with 200 explants per liter showed multiplication rates of 1.7x and 2.3x for agar and thin-film liquid, respectively.
At 40 explants per liter, the multiplication rate was increased to 2.1x for agar and 3.4x for thin-film liquid. Sugar uptake
was greater in liquid than agar and was greater in the higher densities, with the magnitude of the effect dependent on plant
variety. Increased vessel size in the liquid, thin-film system and greater sugar uptake allowed more, larger plants to be
harvested. Alocasia macrorrhizos was cultured in growth medium containing 1μM BA and 5% sucrose with plant densities in the range of 33–330 explants per liter. Dry weight and multiplication rate were
greater in the liquid system than agar with the magnitude of the difference dependent on plant density. With approximately
165 explants per liter, and greater at the initiation of culture, plant density limited growth in both agar and liquid thin-film
systems. In a multiplication medium (3 μM BA and 3 μM ancymidol) plant size was reduced by 50% and 60% (fresh weight) in liquid and agar, respectively. Initial density in the
range of 165–330 explants per liter did not limit growth with the smaller plants in liquid or semisolid multiplication medium.
Sugar uptake was greater in liquid than agar. While ample sugar was present in media for growth at any density on agar, sugar
depletion was limiting growth at highest densities with the larger plants in liquid growth medium. In semisolid agar medium,
sugar uptake by plants was more rapid than diffusion across the agar medium, resulting in non-equilibrium conditions following
the culture cycle. In agitated, liquid medium, a greater transfer of sugars to plant tissue was related to accelerated growth. 相似文献
15.
C. M. Felland L. A. Hull B. A. Barrett A. L. Knight J. W. Jenkins P. A. Kirsch D. R. Thomson 《Entomologia Experimentalis et Applicata》1995,74(2):105-114
Mating disruption treatments for the tufted apple bud moth (TABM),Platynota idaeusalis (Walker), were tested in small plot trials in apple orchards in Pennsylvania. Treatments were evaluated by fruit injury and
by capture of male TABM in traps baited with synthetic pheromone sources or virgin females. The TABM pheromone is a two component
isomeric blend ofE-11-tetradecen-1-ol (E11-14:OH) andE-11-tetradecenyl acetate (E11-14:Ac). A 50∶50 ratio of these two components was used in standard monitoring septa and in mating
disruption treatments released from either hollow fibers (‘fiber’) or PVC tubes (‘PVC’). Other pheromone blends tested included
a 90∶10 ratio of E11-14: Ac and E11-14:OH (‘EAc’) and its reverse (‘EOH’), mixture ‘EAc’ with 30% of the Z-isomers (‘low AEc’),
and a blend similar to the preceding with 2% Z9-12:Ac (‘generic’). These other blends were released from multi tube tape (‘tape’)
or Shin-Etsu type rope (‘rope’) dispensers. Seasonal dispenser release rate in mg ha−1 h−1 was ca. 30 for the ‘rope’ dispensers, 14 for ‘PVC’ and 6 for ‘fiber’. ‘EAc-tape’ and ‘EOH-tape’ were equally effective in
reducing catches of males in traps baited with synthetic lures and in traps baited with virgin females. Both treatments also
reduced fruit injury. ‘EAc-rope’, ‘fiber’ and ‘PVC’ also were generally effective; whereas, the ‘low EAc’ and ‘generic’ treatments
reduced trap capture less than 90% and did not reduce fruit injury. Dispenser density was positively correlated with reduction
in trap capture for the ‘low EAc-rope’ and ‘genericrope’ treatments. Traps loaded with ‘fiber’ dispensers captured more male
TABM than the other treatments in non-pheromone permeated environments. Trap capture of other tortricids was reduced in pheromone
treatments. ‘EAc-rope’ and the ‘TABM’ treatments provided mean (s.e.) percent reduction in trap catch of 99.5 (0.4) and 42.9
(10.1), respectively, for the redbanded leafroller,Argyrotaenia velutinana (Walker), and 90.4 (6.8) and 90.4 (1.3), respectively, for the obliquebanded leafroller,Choristoneura rosaceana (Harris). 相似文献
16.
Summary An improved protocol for shoot regeneration from hypocotyl segments of seedlings from open-pollinated seeds of lingonberry
(Vaccinium vitis-idaea L.) cultivars, ‘Ida’, ‘Splendor’, and ‘Erntesegen’, and a native clone from Newfoundland was developed. The effect of thidiazuron
(TDZ) on adventitious bud and shoot formation from apical, central, and basal segments of the hypocotyl was tested. Highly
regenerative callus was obtained from hypocotyl segments on modified Murashige and Skoog (MMS) medium containing 5–10 μM TDZ. A maximum of 10 buds and 12 shoots per apical segment for seedlings of cultivar ‘Ida’ regenerated on MMS containing
10 μM TDZ. Callus and bud regeneration frequency, callus growth, and number of buds and shoots per regenerating explant depended
not only on the specific segment of the hypocotyl, but also on parental genotype. Inhibition of shoot elongation by TDZ was
overcome by transferring shoot cultures to a shoot proliferation medium containing 1–2 μM zeatin. The optimal concentration of sucrose for shoot elongation was 20 gl−1. Shoots were rooted ex vitro on a 2 peat: 1 perlite (v/v) medium after dipping in 0.8% indole-3-butyric acid, and rooted plants acclimatized readily under
greenhouse conditions. 相似文献
17.
A. H. Price A. D. Tomos D. S. Virk 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(1-2):132-142
Root growth is an important component of the adaptation of rice to drought-prone environments. A hydroponic screen was used
to study root growth of 28 rice varieties. Both maximum root length and adventitious root thickness varied widely between
varieties. In general, japonica varieties had larger root systems than indica varieties. Two F2 populations involving the thick- and long-rooted upland japonica variety ‘Azucena’ and two poor-rooting varieties, namely the upland indica‘Bala’ and the Italian japonica‘Maratelli’, were made and screened in hydroponics. Generation means analysis revealed significant additive and dominance
main effects for the root length traits with a prevalence of dominance gene effects in both crosses. The dominance×dominance
type of non-allelic interactions were important for maximum root length from day 7 to day 28, root volume, root thickness
and root cell length in the cross ‘Bala’בAzucena’. The heritability (broad-sense) estimates varied from low to high for the
traits and displayed differences between populations. This suggested that recombinant lines with improved root traits can
be developed from the two crosses with selection methods that involve some form of progeny evaluation. In a companion paper,
we report the mapping of quantitative trait loci (QTLs) for root growth traits in the ‘Bala’בAzucena’ population using restriction
fragment length polymorphisms (RFLPs).
Received: 5 May 1996 / Accepted: 14 February 1997 相似文献
18.
J. O. Rasmussen S. Waara O. S. Rasmussen 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(1-2):41-49
Recipient protoplasts from three Solanum tuberosum genotypes, cv ‘Folva’ (2n=4x=48), cv ‘Matilda’ (4n) and ‘161 : 14’ (2n), were electrofused with X-ray-irradiated donor protoplasts
from two wild species S. spegazzinii (2n) or S. microdontum×S. vernei (2n). Prior to fusion, protoplasts were fluorescence-labelled with either fluorescein diacetate or scopoletin. Fusion products
were identified by dual fluorescence and selected by micromanipulation or fluorescence-activated cell sorting (FACS). All
putative hybrid plants were analysed by the random amplified polymorphic DNA (RAPD) technique. Our analysis demonstrates that
each asymmetric hybrid plant has an individual and stable profile of donor-specific RAPD bands. The irradiation of donor protoplasts
hampered the growth of selected heterofusion products in a dose-dependent way. Irradiation resulted in donor chromosome elimination,
but not in a dose dependent way, in the tested interval. In asymmetric hybrids with the S. spegazzinii donor 33–68% of the donor-specific RAPD bands were missing, indicating a similar level of chromosome elimination. In asymmetric
hybrid plants with the S. microdontum×S. vernei donor 74–95% of the donor RAPD bands were missing. Chromosome countings revealed that these hybrids had chromosome numbers
equal to or below the chromosome numbers found in the tetraploid recipients. This is the first time that highly asymmetric
hybrid plants between two tetraploid potato recipients and the donor S. microdontum×S. vernei have been obtained.
Received : 16 December 1996 / Accepted: 21 February 1997 相似文献
19.
Tolerance to phosphorus stress was studied in Capsicum annuum L. Chile ancho cv. San Luis and bell pepper cv. Jupiter plants.
Plants were fertilized weekly with Long-Ashton nutrient solution (LANS) modified to supply 0, 11, 22, 44, 66, or 88 g(P) m-3 (P0, P11, P22, P44, P66, P88). Phosphorus stress occurred in both cultivars at P0 and P11, with reduced plant growth and
development. At P0, the lowest percentage of total biomass was directed toward reproductive growth. The root/shoot ratio was
greatest at P0, reflecting greater dry matter partitioning to the root system. Growth of ‘San Luis’ was more sensitive to
phosphorus stress than ‘Jupiter’. A greater percentage of total biomass was directed towards reproductive growth in ‘Jupiter’
than ‘San Luis’. Increasing P nutrition elevated leaf tissue P in both cultivars with highest leaf tissue P at P88. There
were no differences in tissue P between P0 and P11 ‘San Luis’ plants, whereas P0 ‘Jupiter’ plants had the lowest tissue P.
Low P-plants generally had the highest tissue N and lowest S, Mn, and B. In both cultivars, gas exchange was lowest at P0,
as indicated by reduced stomatal conductance (gs) and net photosynthetic rate (PN). Internal CO2 concentration and leaf-to-air vapor pressure difference (VPD) were generally highest with P-stressed plants. Phosphorus use
efficiency, as indicated by PN per unit of leaf tissue P concentration (PN/P), was highest at P11. Generally, no P treatments exceeded the gas exchange levels obtained by P44 (full strength LANS)
plants. Both PN and gs declined during reproductive growth in ‘San Luis’, which fruits more rapidly than ‘Jupiter’, whereas no reduction in gas
exchange occurred with ‘Jupiter’.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
20.
Phosphite is a cost-effective fungicide used to control the pathogen Phytophthora cinnamomi which is damaging the diverse flora of the southwest of Western Australia. Three annual species of the southwest jarrah (Eucalyptus marginata) forest of Western Australia (Pterocheata paniculata, Podotheca gnaphalioides and Hyalosperma cotula), were studied to determine the effect of the fungicide phosphite on the species’ reproduction. Phosphite at concentrations
of 2.5, 5 and 10 g L–1 reduced pollen fertility of Pt. paniculata when plants were sprayed at the vegetative stage. Pollen fertility of all three species was reduced when plants were sprayed
at anthesis with 10 g L–1 phosphite. Seed germination was reduced by phosphite in Pt. paniculata and H. cotula when plants were sprayed in the vegetative stage. Phosphite when sprayed at anthesis at a concentration of 5 g L–1 reduced seed germination of H. cotula. Phosphite at concentrations of 5 and 10 g L–1 killed a proportion of plants from all three species and up to 90% of Po. gnaphalioides plants. The frequent application of phosphite, therefore, may reduce the abundance of annual plants in this ecosystem.
Received: 14 December 2000 / Revision accepted: 10 March 2001 相似文献