共查询到20条相似文献,搜索用时 500 毫秒
1.
2.
Angel Fernández i Martí Toshio Hanada José M. Alonso Hisayo Yamane Ryutaro Tao Rafel Socias i Company 《Sexual plant reproduction》2009,22(3):179-186
Self-compatibility has become the primary objective of most almond (Prunus amygdalus Batsch) breeding programmes in order to avoid the problems related to the gametophytic self-incompatibility system present
in almond. The progeny of the cross ‘Vivot’ (S
23
S
fa) × ‘Blanquerna’ (S
8
S
fi) was studied because both cultivars share the same S
f allele but have a different phenotypic expression: active (S
fa) in ‘Vivot’ and inactive (S
fi) in ‘Blanquerna’. In addition, the microscopic observation of pollen tube growth after self-pollination over several years
showed an unexpected self-incompatible behaviour in most seedlings of this cross. The genotypes of this progeny showed that
the S
fi pollen from ‘Blanquerna’ was not able to grow down the pistils of ‘Vivot’ harbouring the S
fa allele, confirming the active function of this allele against the inactive form of the same allele, S
fi. As self-compatibility was observed in some S
8
S
23 and S
8
S
fa individuals of this progeny, the S
f haplotype may not always be linked to the expression and transmission of self-compatibility in almond, suggesting that a
modifier locus may be involved in the mechanism of self-incompatibility in plants. 相似文献
3.
Iwona Żur Ewa Dubas Elżbieta Golemiec Magdalena Szechyńska-Hebda Franciszek Janowiak Maria Wędzony 《Plant Cell, Tissue and Organ Culture》2008,94(3):319-328
The accumulation of abscisic acid (ABA) and the activities of antioxidative enzymes along with cell metabolic activity were
monitored during androgenesis induction in triticale (×Triticosecale Wittm.). Tested cultivars ‘Mieszko’ and ‘Wanad’ were selected due to their significantly different responses to androgenic
induction. Significant variation was observed in respect of superoxide dismutase activity and endogenous ABA content in anthers
isolated from freshly cut tillers. For both cultivars, tillers pretreatment with low temperature decreased peroxidase activity
by 36%, highly accelerated respiration rate and reduced heat production. At the same time, the level of ABA in ‘Mieszko’ was
increased to the level measured in ‘Wanad’. This effect was associated with higher microspore culture viability and increased
stress tolerance in ‘Mieszko’. Low temperature and metabolic starvation during 4-day anther preculture did not influence activities
of antioxidative enzymes, while it resulted in slight decrease in respiration rate and heat emission. The importance of these
changes for effective androgenesis induction is discussed. 相似文献
4.
Zheng Shi Yiqing Li Shaojun Wang Guobing Wang Honghua Ruan Rong He Yanfei Tang Zengxin Zhang 《Ecological Research》2009,24(6):1257-1265
Soil respiration (R
s) is an important component of the carbon cycle in terrestrial ecosystems, and changes in soil respiration with land cover
alteration can have important implications for regional carbon balances. In southeastern China (Xiashu Experimental Forest,
Jiangsu Province), we used an automated LI-8100 soil CO2 flux system to quantify diurnal variation of soil respiration in a secondary oak forest and a pine plantation. We found that
soil respiration in the pine plantation was significantly higher than that in the secondary oak forest. There were similar
patterns of soil respiration throughout the day in both the secondary oak forest and the pine plantation during our 7-month
study (March–September 2005). The maximum of R
s occurred between 4:00 pm and 7:00 pm. The diurnal variations of R
s were usually out of phase with soil surface (0.5 cm) temperature (T
g). However, annual variation in R
s correlated with surface soil temperature. Soil respiration reached to a maximum in June, and decreased thereafter. The Q10 of R
s in the secondary oak forest was significantly higher than that in the pine plantation. The higher Q10 value in the secondary oak forest implied that it might release more CO2 than the pine plantation under a global-warming scenario. Our results indicated that land-use change from secondary forest
to plantation may cause a significant increase in CO2 emission, and reduce the temperature sensitivity of soil respiration in southeastern China. 相似文献
5.
Guohua Xu Shaoling Zhang Yonghua Yang Caiping Zhao Joseph N. Wolukau 《Acta Physiologiae Plantarum》2008,30(2):233-241
The objective of this study was to examine whether S-RNase plays a specific role in the pre-germinated Pyrus pollen. Effects of exogenous RNase and endogenous S-RNase on concentration of cytosolic-free calcium ([Ca2+]i) variation of pre-germinated Pyrus pollen were studied. [Ca2+]i variation caused by different RNases were complex. In 1 h after being cultured, exogenous RNase, RNase T1 and RNase A, and endogenous incompatible ‘Hohsui’ RNase promoted the [Ca2+]i of ‘Hohsui’ pollen. Acid proteins of ‘Hohsui’ had no remarkable influence on the [Ca2+]i of self-pollen. Endogenous compatible ‘Kohsui’ RNase reduced the [Ca2+]i of ‘Hohsui’ pollen, but compatible ‘Hohsui’ RNase can stimulate the [Ca2+]i of ‘Kohsui’ pollen. RNase T1, RNase A and incompatible ‘Kohsui’ S-RNase can also make ‘Kohsui’ pollen [Ca2+]i increase. Different from ‘Hohsui’ pollen, acid proteins of ‘Hohsui’ pull down the ‘Kohsui’ pollen [Ca2+]i remarkably. Conclusion can be made that during the prophase of pollen germination, endogenous S-RNase has no specific effect
on pollen [Ca2+]i changes. 相似文献
6.
7.
Shelake Rahul Mahadev Angappan Kathithachalam Murugan Marimuthu 《In vitro cellular & developmental biology. Plant》2011,47(5):611-617
In vitro propagation has played a key role for obtaining large numbers of virus free, homogenous plants, and for breeding of plantains
and bananas (Musa spp.). Explant sources utilized for banana micropropagation include suckers, shoot tips, and floral buds. The present study
employed male floral meristems as explant material for micropropagation of hill banana ecotypes (AAB) ‘Virupakshi’ and ‘Sirumalai.’
Immature male floral buds were collected from healthy plants from hill banana growing areas. Exposure of explants to ethyl
alcohol (70%, v/v) for 30 s, then mercuric chloride (0.1%, w/v) for 30 s, followed by three independent rinses of 5 min each in autoclaved, double-distilled water satisfactorily reduced
the contamination. Male floral bud explants were cultured on Murashige and Skoog (MS) basal medium supplemented with different
combinations of 6-benzylaminopurine (BAP), coconut water, naphthaleneacetic acid, gibberellic acid, and additional supplements.
MS medium supplemented with 5 mg l−1 BAP and coconut water (15%) was the most efficient media for shoot initiation and multiple shoot formation (15 shoots from
a single part of a floral bud). The best response for shoot elongation was obtained using the combination of basal MS, 5 mg l−1 BAP, 1 mg l−1 naphthaleneacetic acid and 1.5 mg l−1 gibberellic acid. Regenerated shoots were rooted in basal MS medium within 15–20 d. The rooted plantlets were transferred
to a soil mixture and maintained at a temperature of 25 ± 2°C for 10 d and then at room temperature (30–32°C) for 2 wk, before
transferring to a greenhouse. The regenerated plantlets showed 100% survival. 相似文献
8.
Akiko Sasaki Yu Hagimori Ichiro Yuasa Takayuki Nakatsubo 《Landscape and Ecological Engineering》2012,8(1):107-114
To quantify organic matter mineralization at estuarine intertidal flats, we measured in situ sediment respiration rates using
an infrared gas analyzer in estuarine sandy intertidal flats located in the northwestern Seto Inland Sea, Japan. In situ sediment
respiration rates showed spatial and seasonal variations, and the mean of the rates is 38.8 mg CO2-C m−2 h−1 in summer. In situ sediment respiration rates changed significantly with sediment temperature at the study sites (r
2 = 0.70, p < 0.05), although we did not detect any significant correlations between the rates and sediment characteristics. We prepared
a model for estimating the annual sediment respiration based on the in situ sediment respiration rates and their temperature
coefficient (Q
10 = 1.8). The annual sediment respiration was estimated to be 92 g CO2-C m−2 year−1. The total amount of organic carbon mineralization for the entire estuarine intertidal flats through sediment respiration
(43 t C year−1) is equivalent to approximately 25% of the annual organic carbon load supplied from the river basin of the estuary. 相似文献
9.
Abaydulla G Luo X Shi J Peng F Liu M Wang Y Dai J Fang C 《Antonie van Leeuwenhoek》2012,101(4):725-731
A red-pigmented, Gram-negative, strictly aerobic, rod-shaped bacterium which was motile by gliding, designated strain 1351T, was isolated from the soil of Lengduo, Tibet in China and subjected to a polyphasic taxonomic analysis. The isolate grows
optimally at 30°C and pH 7. It grows with NaCl tolerated up to 1.5% (optimum, 0.5%). Phylogenetic analysis based on the 16S
rRNA gene sequence shows that strain 1351T is closely related to members of the family ‘Cytophagaceae’ closest sequence similarity was observed with similarity with Adhaeribacter terreus (91.8%). The major whole-cell fatty acids are summed feature 4 (containing anteiso-C17:1 B and/or iso-C17:1 I, 29.2%), summed feature 3 (containing C16:1ω6c and/or C16:1ω7c, 13.0%) and iso-C15:0 (12.0%). The predominant menaquinone of strain 1351T is menaquinone-7 (MK-7) and the G+C content of the DNA is 46.8 mol%. According to the phylogenetic evidence and phenotypic
data, strain 1351T is considered to represent a new genus and species of the family ‘Cytophagaceae’ for which the name Rufibacter tibetensis gen nov., sp. nov. is proposed. The type species is R. tibetensis and the type strain is 1351T (=CCTCC AB 208084T = NRRL B-51285T). 相似文献
10.
A. Gadaleta A. E. Blechl S. Nguyen M. F. Cardone M. Ventura J. S. Quick A. Blanco 《Molecular breeding : new strategies in plant improvement》2008,22(2):267-279
Durum wheat (Triticum turgidum L. var. durum) is traditionally used for the production of numerous types of pasta, and significant amounts are also used for bread-making,
particularly in southern Italy. The research reported here centres on the glutenin subunits 1Dx5 and 1Dy10 encoded by chromosome
1D, and whose presence in hexaploid wheats is positively correlated with higher dough strength. In order to study the effects
of stable expression of the 1Dx5 and 1Dy10 glutenin subunits in different durum wheat genotypes, four cultivars commonly grown
in the Mediterranean area (‘Svevo’, ‘Creso’, ‘Varano’ and ‘Latino’) were co-transformed, via particle bombardment of cultured
immature embryos, with the two wheat genes Glu-D1-1d and Glu-D1-2b encoding the glutenin subunits, and a third plasmid containing the bar gene as a selectable marker. Protein gel analyses of T1 generation seed extracts showed expression of one or both glutenin genes in four different transformed durum wheat plants.
One of these transgenic lines, DC2-65, showed co-suppression of all HMW-GS, including the endogenous ones. Transgene stability
in the transgenic lines has been studied over four generations (T1–T4). Fluorescence in situ hybridization (FISH) analysis of metaphase chromosomes from T4 plants showed that the integration of transgenes occurred in both telomeric and centromeric regions. The three plasmids were
found inserted at a single locus in two lines and in two loci on the same chromosome arm in one line. The fourth line had
two transgenic loci on different chromosomes: one with both glutenin plasmids and a different one containing only the construct
with the gene encoding the 1Dy10 glutenin subunit. Segregation of these two loci in subsequent generations allowed establishment
of two sublines, one containing both 1Dx5 and 1Dy10 and the other containing only 1Dy10. Small-scale quality tests showed
that accumulation of Dx5, Dy10 or both in transgenic durum wheat seeds resulted in doughs with stronger mixing characteristics.
A. Gadaleta and A. E. Blechl have contributed equally to this work. 相似文献
11.
Alonso Segura JM Socias I Company R 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(2):151-158
Inbreeding depression has been observed in most fruit trees, negatively affecting the offspring of related parents. This problem
is steadily increasing due to the repeated utilization of parents in breeding programmes. In almond, self-compatibility transmission
from ‘Tuono’ to its offspring remains partially unexplained due to deviations from the expected genotype ratios. In order
to test if these deviations could be due to inbreeding, the S-genotypes of the seedlings of four almond families, ‘Tuono’ (S
1
S
f
) × ‘Ferragnès’ (S
1
S
3
), ‘Tuono’ (S
1
S
f
) × ‘Ferralise’ (S
1
S
3
) and reciprocal crosses were studied. The S-genotype determination of each seedling by separation of stylar S-RNases and by S-allele-specific PCR amplification gave identical results. The ratio of S-genotypes of the family ‘Tuono’ × ‘Ferralise’ was the one least adjusted to the expected 1:1 ratio, because the number of
self-compatible seedlings (S
f
S
3
) was less than a half the number of self-incompatible ones (S
1
S
3
). A mechanism acting against inbreeding would favour cross-breeding in the following generation to increase heterozygosity.
This fact stresses the need to avoid crosses between related parents in fruit breeding programmes. 相似文献
12.
Andrew T. Nottingham Erland Bth Stephanie Reischke Norma Salinas Patrick Meir 《Global Change Biology》2019,25(3):827-838
Terrestrial biogeochemical feedbacks to the climate are strongly modulated by the temperature response of soil microorganisms. Tropical forests, in particular, exert a major influence on global climate because they are the most productive terrestrial ecosystem. We used an elevation gradient across tropical forest in the Andes (a gradient of 20°C mean annual temperature, MAT), to test whether soil bacterial and fungal community growth responses are adapted to long‐term temperature differences. We evaluated the temperature dependency of soil bacterial and fungal growth using the leucine‐ and acetate‐incorporation methods, respectively, and determined indices for the temperature response of growth: Q10 (temperature sensitivity over a given 10oC range) and Tmin (the minimum temperature for growth). For both bacterial and fungal communities, increased MAT (decreased elevation) resulted in increases in Q10 and Tmin of growth. Across a MAT range from 6°C to 26°C, the Q10 and Tmin varied for bacterial growth (Q10–20 = 2.4 to 3.5; Tmin = ?8°C to ?1.5°C) and fungal growth (Q10–20 = 2.6 to 3.6; Tmin = ?6°C to ?1°C). Thus, bacteria and fungi did not differ significantly in their growth temperature responses with changes in MAT. Our findings indicate that across natural temperature gradients, each increase in MAT by 1°C results in increases in Tmin of microbial growth by approximately 0.3°C and Q10–20 by 0.05, consistent with long‐term temperature adaptation of soil microbial communities. A 2°C warming would increase microbial activity across a MAT gradient of 6°C to 26°C by 28% to 15%, respectively, and temperature adaptation of microbial communities would further increase activity by 1.2% to 0.3%. The impact of warming on microbial activity, and the related impact on soil carbon cycling, is thus greater in regions with lower MAT. These results can be used to predict future changes in the temperature response of microbial activity over different levels of warming and over large temperature ranges, extending to tropical regions. 相似文献
13.
Regional variation in the temperature sensitivity of soil organic matter decomposition in China's forests and grasslands 总被引:1,自引:0,他引:1 下载免费PDF全文
Yuan Liu Nianpeng He Jianxing Zhu Li Xu Guirui Yu Shuli Niu Xiaomin Sun Xuefa Wen 《Global Change Biology》2017,23(8):3393-3402
How to assess the temperature sensitivity (Q10) of soil organic matter (SOM) decomposition and its regional variation with high accuracy is one of the largest uncertainties in determining the intensity and direction of the global carbon (C) cycle in response to climate change. In this study, we collected a series of soils from 22 forest sites and 30 grassland sites across China to explore regional variation in Q10 and its underlying mechanisms. We conducted a novel incubation experiment with periodically changing temperature (5–30 °C), while continuously measuring soil microbial respiration rates. The results showed that Q10 varied significantly across different ecosystems, ranging from 1.16 to 3.19 (mean 1.63). Q10 was ordered as follows: alpine grasslands (2.01) > temperate grasslands (1.81) > tropical forests (1.59) > temperate forests (1.55) > subtropical forests (1.52). The Q10 of grasslands (1.90) was significantly higher than that of forests (1.54). Furthermore, Q10 significantly increased with increasing altitude and decreased with increasing longitude. Environmental variables and substrate properties together explained 52% of total variation in Q10 across all sites. Overall, pH and soil electrical conductivity primarily explained spatial variation in Q10. The general negative relationships between Q10 and substrate quality among all ecosystem types supported the C quality temperature (CQT) hypothesis at a large scale, which indicated that soils with low quality should have higher temperature sensitivity. Furthermore, alpine grasslands, which had the highest Q10, were predicted to be more sensitive to climate change under the scenario of global warming. 相似文献
14.
15.
Sparse Ulmus pumila woodlands play an important role in contributing to ecosystem function in semi-arid grassland of northern China. To understand
the key attributes of soil carbon cycling in U. pumila woodland, we studied dynamics of soil respiration in the canopy field (i.e., the projected crown cover area) and the open
field at locations differing in distance (i.e., at 1–1.5, 3–4, 10, and >15 m) to tree stems from July through September of
2005, and measured soil biotic factors (e.g., fine root mass, soil microbial biomass, and activity) and abiotic factors [e.g.,
soil water content (SWC) and organic carbon] in mid-August. Soil respiration was further separated into root component and
microbial component at the end of the field measurement in September. Results showed that soil respiration had a significant
exponent relationship with soil temperature at 10-cm depth. The temperature sensitivity index of soil respiration, Q
10, was lower than the global average of 2.0, and declined significantly (P < 0.05) with distance. The rate of soil respiration was generally greater in the canopy field than in the open field; monthly
mean of soil respiration was 305.5–730.8 mg CO2 m−2 h−1 in the canopy field and 299.6–443.1 mg CO2 m−2 h−1 in the open field from July through September; basal soil respiration at 10°C declined with distance, and varied from ~250 mg
CO2 m−2 h−1 near tree stems to <200 mg CO2 m−2 h−1 in the open field. Variations in soil respiration with distance were consistent with patterns of SWC, fine root mass, microbial
biomass and activities. Regression analysis indicated that soil respiration was tightly coupled with microbial respiration
and only weakly related to root respiration. Overall, variations in SWC, soil nutrients, microbial biomass, and microbial
activity are largely responsible for the spatial heterogeneity of soil respiration in this semi-arid U. pumila woodland. 相似文献
16.
The effect of temperature on the respiration rate of meiofauna 总被引:2,自引:0,他引:2
Summary The effect of temperature on respiration rate has been established, using Cartesian divers, for the meiofaunal sabellid polychaeteManayunkia aestuarina, the free-living nematodeSphaerolaimus hirsutus and the harpacticoid copepodTachidius discipes from a mudflat in the Lynher estuary, Cornwall, U.K. Over the temperature range normally experienced in the field, i.e. 5–20° C the size-compensated respiration rate (R
c) was related to the temperature (T) in °C by the equation Log10
R
c=-0.635+0.0339T forManayunkia, Log10
R
c=0.180+0.0069T forSphaerolaimus and Log10
R
c=-0.428+0.0337T forTachidius, being equivalent toQ
10 values of 2.19, 1.17 and 2.17 respectively. In order to derive the temperature response forManayunkia a relationship was first established between respiration rate and body size: Log10
R=0.05+0.75 Log10
V whereR=respiration in nl·O2·ind-1·h-1 andV=body volume in nl.TheQ
10 values are compared with values for other species derived from the literature. From these limited data a dichotomy emerges: species with aQ
102 which apparently feed on diatoms and bacteria, the abundance of which are subject to large short term variability, and species withQ
101 apparently dependent on more stable food sources. 相似文献
17.
Respiration measurements were made on the entire aboveground parts of young, field-grown hinoki cypress (Chamaecyparis obtusa) trees at monthly intervals over a 5-year period, to examine the effect of temperature on maintenance and growth respiration
coefficients. The respiration rate of the trees was grouped on a monthly basis and then partitioned into maintenance and growth
components. The maintenance respiration coefficient increased exponentially with air temperature. The maintenance respiration
coefficient at a temperature of 0°C and itsQ
10 value were 0.205 mmol CO2 g−1 d.w. month−1 and 1.81, respectively. The growth respiration coefficient, which was virtually independent of temperature, had a mean value
of 38.06±1.95 (SE) mmol CO2g−1 d.w. The growth rate increased exponentially with increasing temperature up to a peak at around 18°C, and thereafter declined,
thereby resulting in the growth respiration rate being increasingly less sensitive to increasing air temperature. The reported
decreases in theQ
10 value of total respiration with increasing air temperature is due to the way in which the growth component of respiration
responds to temperature. 相似文献
18.
Exponential growth of “snow molds” at sub-zero temperatures: an explanation for high beneath-snow respiration rates and Q
10 values 总被引:2,自引:0,他引:2
Numerous studies have demonstrated exceptionally high temperature sensitivity of the beneath-snow respiratory flux in cold-winter
ecosystems. The most common, but still untested, explanation for this high sensitivity is a physical one based on the observation
that water availability in soils increases exponentially as soils warm from −3 to 0°C. Here, we present evidence for a biological
hypothesis to explain exponential kinetics and high Q
10 values as beneath-snow soils warm from −3 to 0°C during the early spring in a high-elevation subalpine forest. First, we
show that some of the dominant organisms of the beneath-snow microbial community, “snow molds”, exhibit robust exponential
growth at temperatures from −3 to −0.3°C. Second, Q
10 values based on growth rates across the temperature range of −2 to −0.3°C for these snow molds vary from 22 to 330. Third,
we derive an analytical equation that combines the relative contributions of microbial growth and microbial metabolism to
the temperature sensitivity of respiration. Finally, we use this equation to show that with only moderate snow mold growth
(several generations), the combined sensitivities of growth and metabolism to small changes in beneath-snow soil temperature,
create a double exponential in the Q
10 function that may explain the extremely high (~1 × 106) Q
10 values observed in past studies. Our biological explanation for high Q
10 levels is supported by several independent studies that have demonstrated build up of microbial biomass under the snow as
temperatures warm from −2 to 0°C. 相似文献
19.
O. Urban A. Ač J. Kalina T. Priwitzer M. Šprtová V. Špunda M. V. Marek 《Photosynthetica》2007,45(3):392-399
Temperature responses of carbon assimilation processes were studied in four dominant species from mountain grassland ecosystem,
i.e. Holcus mollis (L.), Hypericum maculatum (Cr.), Festuca rubra (L.), and Nardus stricta (L.), using the gas exchange technique. Leaf temperature (T
L) of all species was adjusted within the range 13–30 °C using the Peltier thermoelectric cooler. The temperature responses
of metabolic processes were subsequently modelled using the Arrhenius exponential function involving the temperature coefficient
Q
10. The expected increase of global temperature led to a significant increase of dark respiration rate (R
D; Q
10 = 2.0±0.5), maximum carboxylation rate (V
Cmax; Q
10 = 2.2±0.6), and maximum electron transport rate (J
max; Q
10 = 1.6±0.4) in dominant species of mountain grassland ecosystems. Contrariwise, the ratio between J
max and V
Cmax linearly decreased with T
L [y = −0.884 T
L + 5.24; r
2 = 0.78]. Hence temperature did not control the ratio between intercellular and ambient CO2 concentration, apparent quantum efficiency, and photon-saturated CO2 assimilation rate (P
max). P
max primarily correlated with maximum stomatal conductance irrespective of T
L. Water use efficiency tended to decrease with T
L [y = −0.21 T
L + 8.1; r
2 = 0.87]. 相似文献
20.
J. Perry Gustafson Xue-Feng Ma Viktor Korzun John W. Snape 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(4):793-800
A consensus map of rye (Secale cereale L.) was constructed using JoinMap 2.0 based on mapping data from five different mapping populations, including ‘UC90’ × ‘E-line’,
‘P87’ × ‘P105’, ‘I0.1-line’ × ‘I0.1-line’, ‘E-line’ × ‘R-line’, and ‘Ds2’ × ‘RxL10’. The integration of the five mapping populations resulted in a 779-cM map
containing 501 markers with the number of markers per chromosome ranging from 57 on 1R to 86 on 4R. The linkage sizes ranged
from 71.5 cM on 2R to 148.7 cM on 4R. A comparison of the individual maps to the consensus map revealed that the linear locus
order was generally in good agreement between the various populations, but the 4R orientations were not consistent among the
five individual maps. The 4R short arm and long arm assignments were switched between the two population maps involving the
‘E-line’ parent and the other three individual maps. Map comparisons also indicated that marker order variations exist among
the five individual maps. However, the chromosome 5R showed very little marker order variation among the five maps. The consensus
map not only integrated the linkage data from different maps, but also greatly increased the map resolution, thus, facilitating
molecular breeding activities involving rye and triticale. 相似文献