查看更多>>摘要：Strawberry is a high-value horticultural crop with a global market and it has a strong regional importance in production areas such as Florida. Strawberry growers face many challenges related to weather, cultivation, and markets. Decision support tools can help optimize strawberry production but require sound models or other predictive tools as a foundation. The goal of this study was to improve a new CROPGRO-Strawberry model in the Decision Support System for Agrotechnology Transfer (DSSAT) using experimental data with observations from different seasons and multiple cultivars. Model improvements were made in three primary areas: 1) cardinal temperatures for different development processes, 2) a module for the dynamic assimilate partitioning based on photothermal age, and 3) improvement of the cultivar and ecotype coefficients. The model predicts the growth, development, and fruit production of strawberry over time using weather, soil, management and physiological parameters as inputs. Overall, the results show a good simulation of development and growth (d = 0.77 to 0.99, RRMSE = 0.26 to 0.68), but an overestimation of vegetative growth during the early season. Periodic and cumulative fruit harvests were well-simulated (d = 0.91, RRMSE 0.47), capturing the seasonal dynamics and representing differences among cultivars and harvest intervals. A strategic analysis showed the applicability of the crop model to understand and manage the impact of seasonal climate variability on total strawberry yield as well as the distribution of fruit production across different harvest months. Future work should include improvements in the simulation of vegetative growth and evaluation against new datasets representing different production environments and cultivars. The improved CROPGRO-Strawberry model will enable future work on applications to other specialty crops where modeling of continuous fruiting and multiple harvests of individual fruit instead of one end-of-season harvest is desired.
查看更多>>摘要：Cytoplasmic male sterility (CMS) system is most important genetic mechanism for affordable and genetically homogenous hybrid seed production. The present study was aimed to evaluate the CMS lines and their maintainers for floral traits as well as assess suitability of mitochondrial DNA (mtDNA) markers to distinguish the fertile/sterile plants at seedling stage. Morphological observations revealed that introgression of CMS trait significantly reduced flower size (length, diameter), petal size (length, width), stigma and anther length. Out of five mtDNA markers, namely Orf138, orf222-orf224, atp6-orf224, Orf138 and BnTR4, two markers (Orf138 and orf222-orf224) exhibited dominant pattern and clearly distinguished CMS lines from their fertile maintainers. However, atp6-orf 224 and BnTR4 showed polymorphic amplicons of different size between them. These new CMS lines have great potential in hybrid breeding and hybrid seed production in Indian cauliflower. The two mtDNA markers (Orf138 and orf222-orf224) will be useful for early detection of Ogura CMS system during introgression programme and for clarification of doubtful seeds.
Verheul, Michel J.Maessen, Henk F. R.Paponov, MartinaPanosyan, Anush...
11页
查看更多>>摘要：Studies of whole-plant responses of tomato to light environments are limited and cannot be extrapolated from observations of seedlings or short-term crops in growth chambers. Effects of artificial light sources like high pressure sodium (HPS) and light emitting diodes (LED) are mainly studied as supplement to sunlight in greenhouses. Since natural sunlight is almost neglectable in Norway during wintertime, we could study effects of different types of artificial light on crop growth and production in tomato. The goal of this experiment was to quantify the effects of artificial HPS top-light, installed at the top of the canopy, and LED inter-light, installed between plant rows, on fresh and dry matter production and fruit quality of greenhouse tomatoes under controlled and documented conditions. Our aim was to optimize yield under different light conditions, while avoiding an unfavourable source-sink balance. Tomato plants were grown under HPS top light with an installed capacity of 161, 242 and 272 W m- 2 combined with LED inter-light with an installed capacity of 0, 60 or 120 W m- 2. We used stem diameter as a trait to regulate air temperature in different light treatments in order to retain plant vigour. Results show that both HPS top light and LED inter-light increased tomato yield. However, the positive effect of supplemental LED inter-light decreased at higher amounts of HPS top light. Under the conditions in this experiment, with neglectable incoming solar radiation, an installed amount of 242 Watt m-2 HPS top light and a daily light integral (DLI) of 30 mol m-2 day-1 resulted in best light use efficiency (in gram fresh tomato per mol). Addition of LED inter-light to HPS top light reduced light use efficiency. Results show that winter production using artificial light in Norway is more energy efficient compared to production under sunlight in southern countries. Results can be used for modelling purposes.
Brand, Mark H.Obae, Samuel G.Mahoney, Jonathan D.Connolly, Bryan A....
16页
查看更多>>摘要：Speciation in Aronia is complex based on Amplified Fragment Length Polymorphism (AFLP) and ploidy analysis of 132, mostly wild, accessions. There are four species of Aronia and seven taxonomic groups comprised of species by ploidy combinations. A. melanocarpa can be diploid or tetraploid, with diploid forms occurring in New England and tetraploid forms occurring primarily outside of New England. A. arbutifolia was only found as a tetraploid and did not appear to occur throughout parts of New England as is generally accepted. It is likely that numerous misidentifications of A. arbutifolia have occurred historically. Almost all wild A. prunifolia were tetraploid, with the exception of a single triploid plant. Evidence from AFLP analysis and several accessions expressing a continuum of morphological characteristics between those of A. arbutifolia and A. melanocarpa suggest that A. prunifolia is of interspecific hybrid origin. The occurrence of a natural triploid A. prunifolia accession and our ability to easily create triploid A. prunifolia progeny from diploid A. melanocarpa by tetraploid A. arbutifolia crosses supports the hybrid formation of the A. prunifolia species. Hybrid A. prunifolia origin is also supported by the prevalence of A. prunifolia accessions in geographic areas where A. arbutifolia and diploid A. melanocarpa interface. Most likely, tetraploid A. prunifolia found in the wild result from repeated formation of triploid F1 interspecific hybrids and the triploid bridge mechanism. AFLP analysis, along with morphology and phenology, suggest that a new species of black-fruited Aronia (melanocarpaS) exists in the southern part of the A. melanocarpa geographic range. A. melanocarpaS plants are placed on a separate branch of the AFLP dendrogram that is separate from other Aronia species. Several accessions with large, wide leaves, large fruits and nonrhizomatous growth were found to be A. mitschurinii, an intergeneric hybrid between Aronia and Sorbus. All A. mitschurinii accessions were tetraploid.
查看更多>>摘要：Fungal diseases are a leading cause of crop destruction. The antifungal impact of plasma technology emulation against phytopathogenic fungi is documented in this research. The purpose of this research was to analyze the impact of plasma technology emulation against mycelium growth and spore germination of Colletotrichum gloeosporioides, a causal agent of anthracnose disease in pepper (Capsicum annuum L.) seeds and its effect on pepper seed quality. The emulation of plasma condition in liquid media was simply created by treating sterilized water or hydrogen peroxide (H2O2) solution with UV-C irradiation to obtain the emulation of plasma activated water (EPAW) and plasma activated H2O2 solution (EPAS-H2O2), respectively. Accordingly, in vitro study, mycelium and spores of C. gloeosporioides fungi like (Cgfl) were treated with sterilized water (control), H2O2 solution at 1, 3 and 5%, EPAW and EPAS-H2O2 at 1, 3 and 5% for 60 min. The treated mycelium and spores were placed on PDA medium and incubated at 25 +/- 3 degrees C. The results revealed that only EPAS-5% H2O2 treatment completely inhibited both mycelium growth and spore germination. Spores were more sensitive to EPAW and EPAS-H2O2 than mycelium. Under scanning, the electron microscope (SEM) showed that the EPAW and EPASH(2)O(2) condition destroyed the cell structure of fungal pathogens, leading to the loss of cell membrane integrity and morphological changes. The effects of 5% H2O2, EPAW and EPAS-5% H2O2 on the quality of artificially inoculated pepper seeds were determined in comparison with fungicide (0.15% w/v captan) treated seeds and non-treated seeds (only water). The results indicated that EPAS-5% H2O2 showed the best result to suppress the seed infection and improved seed germination as compared to other treatments, and stimulated seed quality as employing high germination index, seedling growth rate and fresh and dry weight of seedlings. This study implies that the application of plasma technology emulation is the simple and innovative treatment, which proved to be extremely effective towards seed decontamination and enhancement of pepper seed quality.
查看更多>>摘要：The use of the GreenTray (R) TIS bioreactor for the in vitro analysis of the interaction between plantlets and two Plant Growth-Promoting Microorganisms (PGPMs) (Pseudomonas oryzihabitans PGP01 and Cladosporium ramotenellum PGP02) is reported herein. This in vitro culture system improved micropropagation of Prunus Rootpac 20 (R) rootstock, showing greater shoot length and fresh weight compared with culture in semisolid agar-containing medium. Plant responses in co-culture with the PGPMs, their ability to control endophytes growth in the culture media and hormonal changes associated to plant growth were studied in the GreenTray (R) culture system. Inoculation with P. oryzihabitans PGP01 had no significant effects, whereas C. ramotenellum PGP02 considerably reduced endophytes population after 5 days post inoculation. However, the fungi overgrew the plants roots seriously reducing their growth. These results suggested the effect of the medium pH as a factor to control microbial endophytic growth in the culture medium. A higher P. oryzihabitans PGP01 concentration was inoculated in culture media previously adjusted to pH 5.7 or 7, observing an increased number of roots when plantlets were co-cultured for 15 days with the bacterium in medium adjusted to pH 5.7. This was associated with changes in the levels of IAA in the culture medium, and higher leaf chlorophyll contents than in the non-inoculated cultured plantlets. P. oryzihabitans PGP01 was not able to reduce endophytes growth in either of both media pHs. Altogether, the GreenTray (R) bioreactor was shown as an efficient system to in vitro micropropagate RP-20 explants as well as to monitor its interaction with PGPMs.
查看更多>>摘要：The present study focuses on examining the effect of phenylmethylsulfonyl fluoride (PMSF) at three distinct temperatures: 5 degrees C, 10 degrees C and room temperature (RT, i.e., 25 +/- 2 degrees C) on the postharvest attributes of Dianthus chinensis flower stems. The flower stems with the most mature floral bud at the paint brush stage (i.e., one day before anthesis) were harvested and uniformly re-cut in the laboratory. These stems were then divided into three groups, with each group further categorized into four sets. The three groups of flower stems were stored for 72 h in distilled water (wet stored) at 5 degrees C, 10 degrees C and RT, respectively. At each temperature, one set designated as control was kept unpulsed and the other three sets were pulsed for 1 h with 0.05 mM PMSF before, during (i.e., after 35 1/2 h) and after storage, respectively. After 72 h wet storage and PMSF pulse, the flower stems were transferred to conical flasks containing 0.05 M sucrose and the effect of different treatments was assessed in the subsequent days at room temperature. Flower stems treated with PMSF pulse or cold storage individually or in combination showed significant improvement of vase life, with the maximum value of 22 days registered for flower stems pulsed with PMSF before wet storage at 5 degrees C for 72 h, which was 14, 12 and 5 days more than the control at RT, 10 degrees C and 5 degrees C, respectively. The improved vase life of flower stems was marked by enhanced floral diameter, higher levels of soluble proteins and sugars as compared to the control. The flower stems with improved longevity maintained lower content of total phenols and higher membrane stability index, besides exhibiting a significant alleviation in the deteriorating effects of lipid peroxidation and lipoxygenase activity on membrane integrity. Further, the flower stems with improved postharvest characteristics were also found to be associated with elevated activity of antioxidant enzymes like superoxide dismutase, catalase, and ascorbate peroxidase.
查看更多>>摘要：Banana (Musa spp.) is an important tropical fruit with high economic value, however, Fusarium wilt disease is a critical factor affecting the sound development of the banana industry. Different cultivars of banana exhibit a high degree of genetic variability for resistance to Fusarium wilt. Compared with Cavendish banana (Musa spp. AAA group), Dajiao (Musa spp. ABB group) has superior disease resistance and provides an excellent test material for the isolation and characterization of disease resistance genes. In this study, a Dajiao candidate gene, MpbHLH (basic helix-loop-helix), an encoding ICE1-like protein transcription factor (TF), was cloned and characterized. Real-time quantitative PCR (qPCR) results revealed that MpbHLH transcript levels were strongly induced under cold treatment, salt, and dehydration. Overexpression of MpbHLH in Foc TR4-sensitive Cavendish banana showed that the transgenic lines had superior resistance to Fusarium wilt compared with the wild-type (WT). Proteomic analysis showed that phenylalanine ammonia lyase (PAL) and peroxidase (POD) were highly expressed in transgenic plants. Physiological experiments further revealed that transgenic plants, especially their roots, had high POD activity. Taken together, overexpression of MpbHLH in banana may extensively activate stress-related genes. In particular, the activity of POD increases the resistance of transgenic banana to Fusarium wilt by enhancing the reactive oxygen species (ROS) scavenging system of a transgenic plant.
查看更多>>摘要：Apples were treated with gamma-aminobutyric acid (GABA) to investigate its effect on blue mold, reactive oxygen species (ROS) metabolism and GABA shunt. The results showed that GABA significantly inhibit blue mold of apples. Further studies demonstrated that GABA remarkably increased H2O2, ascorbic acid, and glutathione contents; superoxide dismutase, NADPH oxidase, catalase, glutathione reductase, ascorbate peroxidase, dehydroascorbate reductase, and monodehydroascorbate reductase activities in apple fruit. GABA also activated glutamate decarboxylase, glutamate dehydrogenase and glutamate synthase, while inhibited GABA transaminase and succinate hemialdehyde dehydrogenase in apples. GABA treatment increased endogenous GABA, pyruvic acid and glutamate contents in the fruit. In addition, exogenous GABA dipping up-regulated MdMT, MdMS, MdSAMS, MdSAMDC, MdODC, MdADC and MdSPDS, and down-regulated MdPAO and MdDAO in apples. These findings indicate that GABA enhances disease resistance in apples through regulation of GABA shunt, ROS and polyamine metabolism.
查看更多>>摘要：Sparkleberry (Vaccinium arboreum), a native species, has the potential as a blueberry rootstock due to its broader adaptation and less yield loss during mechanical harvesting. However, propagating sparkleberry on a large scale is difficult and little information about its seed germination can be found. To improve sparkleberry germination rate, a germination study was conducted with seeds collected in November and December 2018. Seeds were treated with gibberellic acid (GA(3)) at three levels (0, 500, and 1,000 mg L-1) and cold stratification at four levels (0, 3, 6, and 9 weeks). Emergence percentage (EP), emergence index (EI), and the number of days needed for the first seed to emerge (NDE) were recorded and calculated. Results showed that the combination of GA(3) and cold stratification could increase V. arboreum EP, while in the control (no GA(3) or cold stratification) no seeds germinated by the end of the experiment. Seeds collected from November treated with 500 mg L-1 GA(3) and 9-week cold stratification reached an EP at 70.4% with 12.6 DNE. Seeds collected from December treated with 1,000 mg L-1 GA(3) and 3-week cold stratification reached an EP at 61.2% with 19 DNE. In conclusion, applying GA(3) at 500 mg L-1 or 1,000 mg L-1 combined with weeks of cold stratification can be used to improve V. arboreum seed germination.
NSTL
Elsevier