采后浸钙对库尔勒香梨果实Ca、Mg、K含量及萼端黑斑病的影响

2012～2013年研究采后浸钙处理对库尔勒香梨果实Ca、Mg、K含量及萼端黑斑病发生的影响。结果表明,浸钙处理提高了香梨果皮和果肉中的Ca、Mg含量和Ca/Mg,其中6%CaCl2处理对提高Ca含量的效果更显著,同时,浸钙处理降低了K含量和K/Ca,其中6%CaCl2处理对降低K/Ca的效果更显著。浸钙处理,能够明显降低萼端黑斑病的发生,在3个处理中,以4%CaCl2溶液处理对防治萼端黑斑病的效果最好,发病率为0,6%CaCl2和8%CaCl2溶液处理的发病率比对照分别降低74.4%和79.3%。     

香梨生长季果实和叶片矿质元素含量的变化

以‘库尔勒’香梨为试材,研究了其在生长发育期间果实和叶片中N、P、K、Ca、Mg元素的含量变化,旨在为‘库尔勒’香梨合理施肥提供指导.结果表明:随着果实生长发育,香梨叶片中P、K、Ca含量呈下降趋势,Mg含量呈上升趋势,N含量波动较大,P与Mg呈显著负相关,K与Mg呈负相关;香梨果实中N、P、K、Ca、Mg含量随果实生长逐渐降低,N与P、K、Ca、Mg呈显著正相关,P与K呈显著正相关,K与Ca呈极显著正相关,Ca与Mg呈显著正相关.     

‘库尔勒香梨’花萼端不同形状果实的矿质元素和内源激素含量比较

以库尔勒香梨(Pyrus sinkiangensis Yü‘Korla Xiangli’)果实为材料,研究了脱萼不突起、宿萼不突起和宿萼突起等3种形状以及同一形状的果柄端、胴部和花萼端等3个部位的矿质元素、内源激素和品质差异。结果表明,果皮的N、Ca、Mg、B含量较果肉高,而N/Ca和K/Ca则较果肉低;宿萼突起果中,N、K、P含量和N/Ca显著高于脱萼不突起果和宿萼不突起果;花萼端Ca含量显著低于果柄端和胴部,而N含量和N/Ca均显著高于果柄端和胴部。果皮的IAA、ZR和ABA含量较果肉高,并且宿萼突起果的IAA含量和(ZR+IAA+GA3)/ABA显著高于脱萼不突起果和宿萼不突起果,ABA含量则显著低于脱萼不突起果;果实不同部位的各内源激素分布未发现明显变化规律。脱萼不突起果综合品质好于宿萼果,花萼端可溶性固形物和维生素C含量显著高于果柄端和胴部。     

早酥梨果实木栓化褐变与矿质营养的关系

为探究早酥梨果实木栓化褐变的原因,以早酥梨木栓化褐变病果和健康果为测试样品,采用溴乙酰乙酸法和电感耦合等离子体发射光谱仪分别测定果皮和果肉中的木质素及主要矿质元素K、Ca、Na、P、Mg、Fe、Mn、Cu、Zn、B等的含量。结果表明,早酥梨木栓化褐变病果果肉中木质素含量显著高于健康果的(P0.05),而果皮中的木质素含量显著低于健康果的(P0.05);同健康果相比,早酥梨木栓化褐变病果中含量显著低的矿质元素有Mg、B、Cu、Zn、K、P和Mn元素;果肉中的木质素含量与K、P、和Mg元素呈显著负相关,果肉中的木质素含量与Mg、B、Cu、P、Fe、Zn、Ca元素呈显著正相关。本研究认为,早酥梨果实木栓化褐变是一种缺素性生理病害,果园可采取配方施肥措施加以防治。     

库尔勒香梨化学锈斑的综合防治

库尔勒香梨化学锈斑是库尔勒香梨果实在低温贮藏后期经常发生的一种最严重的生理性病害。该病的主要症状是在库尔勒香梨果皮表面(通常是绿色部分)出现不规则且平坦的褐色至深褐色病斑。发病初期病斑面积较少,皮下果肉组织正常,发病后期病斑可延至整个果面,部分果肉也变褐。病果极易染菌而腐烂,常造成重大经济损失。近年来随着库尔勒香梨贮藏量的逐年增加,加强对该病的防治势在必行。1采取合理的栽培技术,提高库尔勒香梨品质在果实采收前应控制氮肥的施用,适量施用磷钾肥,以改善果实品质,降低化学锈斑发生率。另外通过合理修剪,使树冠透光,促…     

库尔勒香梨萼端黑斑病发生的原因

2007-2009年,在新疆库尔勒地区,香梨在贮藏期发生一种此前极少发生的病害,即萼端黑斑。为了探明该病害的发生原因,对香梨健康果与萼端黑斑果果实品质、矿质元素等方面进行了比较研究,同时对黑斑病果进行病原学鉴定。结果表明,香梨萼端黑斑病果实较健果可溶性固形物含量低,且病果中公梨(花萼宿存或未脱落净的)所占比例高达80%;矿质元素测定结果表明,病果中Ca含量低于健果,而N/Ca、K/Ca均高于健果,且果实花萼端钙含量最低,氮含量以及N/Ca、K/Ca最高。柯赫氏证病法结果显示,分离得到的枝孢霉属(Cladosporium cladosporioides)和链格孢属(Alternaria alternata)真菌为非致病菌。初步认为,库尔勒香梨萼端黑斑病是一种由于果实品质下降和N/Ca、K/Ca失调及缺钙引起的生理性病害。     

珊夏苹果果实生理病害与Ca等无机成分含量的关系

测定了珊夏苹果生理病害果实的Ca、Mg、K含量，病害果的Ca含量显著低于健全果，(Mg K)／Ca阳离子比率显著高于健全果，斑点性生理病害和果肉褐变是由低Ca和高(Mg K)／Ca引起。     

钙分布和定位影响“富士”苹果痘斑病的发生

据《中国农业科学》2013年第18期《“富士”苹果痘斑病与Ca营养、分布和定位》（作者董宇等）报道，以“短枝富士”苹果为材料，用原子吸收法测定患痘斑病果实（简称病果）与健康果实（简称健果）的顶、中、底部皮组织中Ca、K和Mg含量。同时，用X射线能谱仪分析果皮和果肉组织中Ca、K和Mg的微区分布，     

无机元素N、P、K含量与库尔勒香梨腐烂病严重度间的关联分析

以不同病害程度的库尔勒香梨树和果园为试材，测定其一年生枝条韧皮部N、P、K含量及土壤中N、P、K含量，在不同浓度梯度的N、P、K培养基上接种库尔勒香梨腐烂病菌，观察并记录菌落形态、生长速率及产孢情况，分析N、P、K含量与病害程度之间的相关性，研究了无机元素N、P、K与库尔勒香梨腐烂病之间的关系，以期为库尔勒香梨腐烂病的综合防治提供参考依据。结果表明：不同浓度N、P、K对菌落生长的影响表现为随着N含量的增加，病菌生长速率降低，随着P、K浓度的增加，病菌生长速率呈先上升后下降的趋势。库尔勒香梨腐烂病发病程度与土壤K含量及树体K含量呈显著负相关，与土壤及树体N/K、P/K比例均呈显著正相关，即N/K、P/K比例越高，腐烂病发生越严重。果园管理应适量施用氮肥和钾肥，可减轻库尔勒香梨腐烂病发生程度。     

秋锦苹果苦痘病与果实矿质元素含量和品质相关性的研究

以套袋秋锦苹果为试材,测定了苦痘病果与健果不同部位矿质含量及可溶性固形物的含量。结果表明:矿质元素含量果皮果肉,苦痘病果实的Ca含量低于健果,果皮中尤为明显;苦痘病果N、P、K、B含量及N/Ca、K/Ca、B/Ca、P/Ca均高于健果,N/K、N/P和K/P差异不明显;果皮不着色面Ca含量均低于着色面,而N含量均高于着色面。苦痘病果可溶性固形物含量显著高于健果。果皮各矿质元素之间以及各矿质元素与SSC间存在较密切的相关性。     

Fruit growth,cuticle deposition,water uptake,and fruit cracking in jostaberry,gooseberry, and black currant

Fruit cracking after rain limits the production of a number of crops, including some Ribes species. To gain a better understanding of the factors involved in cracking, fruit growth, deposition of the cuticular membrane (CM), water uptake and fruit cracking were studied in black currant (Ribes nigrum L. cv. Zema), gooseberry (Ribes uva-crispa L. cv. Rote Triumph), and jostaberry (Ribes nidigrolaria B. cv. Jostine). Fruit surface area and fresh mass increased continuously throughout development, whereas deposition of the CM was biphasic. CM mass per fruit increased rapidly up to 42, 41, and 49 days after full bloom (DAFB) in black currant, gooseberry, and jostaberry, respectively. Thereafter, CM mass per fruit remained constant in gooseberry and jostaberry or increased at a lower rate in black currant. The cessation of or reduced rate of CM deposition resulted in a decrease in CM mass per unit area in all berries. Elastic strain of the CM at maturity averaged 23.8% and 19.5% in gooseberry and jostaberry, respectively, and only 8.2% in black currant. Microcracks in the CM were observed first in gooseberry and jostaberry 64 DAFB, whereas there were no microcracks in black currant. Water uptake into mature detached berries was linear over 2 h of incubation. Rates of uptake were highest in gooseberry followed by black currant and jostaberry. Relative uptake was similar via the cut end of the pedicel (32.1%), the apex of the fruit (34.7%) and the fruit surface (33.2%). Rates of water uptake through the fruit surface were positively related to surface area. Average fruit water potential for black currant, gooseberry, and jostaberry was −2.14 ± 0.17, −1.24 ± 0.03, and −1.89 ± 0.20 MPa, while the permeability for osmotic water uptake was 7.7 ± 0.4 × 10⁻⁸, 5.2 ± 0.1 × 10⁻⁸, and 3.3 ± 0.3 × 10⁻⁸ m s⁻¹. Incubating whole fruit in deionized water for 72 h resulted in more cracked jostaberries (94%) than black currants (74%) or gooseberries (50%). A comparison of our findings in Ribes berries with published data for the sweet cherry drupe revealed that the berries fitted the relationships established in sweet cherry among fruit growth, cuticle deposition, strain of the cuticle, microcracking, permeability for osmotic water uptake, frequency of stomata and cracking. The Ribes berries were less susceptible to cracking than sweet cherry.     

Similitude,similarity, and scaling

An exceptionally rich and colorful literature, drawn in almost equal parts from pure mathematics, from the sciences, and from the technologies, has grown up over the years, which bear in different ways on the topics under discussion. It is the intent of the present paper to survey this far-flung literature, point out some of the commonalities and interrelationships which underlie it, and briefly indicate how it has been and can be applied. To my knowledge, this kind of review has not been attempted before.     

Climatic, landform, microtopographic, and overstory canopy controls of tree invasion in a subalpine meadow landscape, Oregon Cascades, USA

Tree invasions have been documented throughout Northern Hemisphere high elevation meadows, as well as globally in many grass and forb-dominated ecosystems. Tree invasions are often associated with large-scale changes in climate or disturbance regimes, but are fundamentally driven by regeneration processes influenced by interactions between climatic, topographic, and biotic factors at multiple spatial scales. The purpose of this research was to quantify spatiotemporal patterns of meadow invasion; and how climate, larger landforms, topography, and overstory trees have interactively influenced tree invasion. We combined airborne Light Detection and Ranging (LiDAR) characterizations of landforms, topography, and overstory vegetation with historical climate, field measurements of snow depth, tree abundance, and tree ages to reconstruct spatial and temporal patterns of tree invasion over five decades in a subalpine meadow complex in the Oregon Cascade Range, USA. Proportion of meadow occupied by trees increased from 8?% in 1950 to 35?% in 2007. Larger landforms, topography, and tree canopies interactively mediated regional climatic controls of tree invasion by modifying depth and persistence of snow pack, while tree canopies also influenced seed source availability. Landscape context played an important role mediating snow depth and tree invasion; on glacial landforms tree invasion was negatively associated with spring snowfall, but on debris flows tree invasion was not associated with snow fall. The importance of snow, uncertain climate change impacts on snow, and mediation of snow by interacting and context dependent factors in complex mountain terrain poses substantial hurdles for understanding how these ecotones may respond to future climate conditions.     

Wetlands, carbon, and climate change

Wetland ecosystems provide an optimum natural environment for the sequestration and long-term storage of carbon dioxide (CO₂) from the atmosphere, yet are natural sources of greenhouse gases emissions, especially methane. We illustrate that most wetlands, when carbon sequestration is compared to methane emissions, do not have 25 times more CO₂ sequestration than methane emissions; therefore, to many landscape managers and non specialists, most wetlands would be considered by some to be sources of climate warming or net radiative forcing. We show by dynamic modeling of carbon flux results from seven detailed studies by us of temperate and tropical wetlands and from 14 other wetland studies by others that methane emissions become unimportant within 300 years compared to carbon sequestration in wetlands. Within that time frame or less, most wetlands become both net carbon and radiative sinks. Furthermore, we estimate that the world’s wetlands, despite being only about 5–8 % of the terrestrial landscape, may currently be net carbon sinks of about 830 Tg/year of carbon with an average of 118 g-C m^?2 year^?1 of net carbon retention. Most of that carbon retention occurs in tropical/subtropical wetlands. We demonstrate that almost all wetlands are net radiative sinks when balancing carbon sequestration and methane emissions and conclude that wetlands can be created and restored to provide C sequestration and other ecosystem services without great concern of creating net radiative sources on the climate due to methane emissions.     

Up-regulation of mRNA expressions of fas,bcl-2, bim,bax, caspase-3, caspase-9, and bcl2l12 in K562 treated with bortezomib

AIM: To detect the treatment of K562 leukemia cells with bortezomib altering the expression of genes fas, bcl-2, bcl2l12, bim, bax, caspase-9 and caspase-3.METHODS: MTT assay was used to detect the inhibition of proliferation. Apoptosis was detected by Annexin-V staining and mitochondrial transmembrane potential (Δψm). RT-PCR was used to analyze the mRNA expressions of fas, bcl-2, bcl2l12, bim, bax, caspase-3 and caspase-9.RESULTS: Bortezomib caused a time- and dose-dependent inhibition of cell proliferation and IC50 of 24 h and 48 h were 161.41 nmol/L and 96.33 nmol/L, respectively. At the concentration of 104 nmol/L, bortezomib induced apoptosis in a time-dependent manner, including increasing annexin-V positivity and decreasing the Δψm. RT-PCR showed that bortezomib up-regulated the mRNA expression of fas, bcl2l12, caspase-9 and caspase-3, but mRNA expressions of bcl-2, bim and bax did not changed obviously.CONCLUSION: Bortezomib inhibits the proliferation of K562 and induces apoptosis, in which fas, bcl2l12, caspase-9 or caspase-3 gene is one of the main genes taking part in.     

氮磷钾硼肥配施对青花菜养分吸收分配及产量和品质的影响

研究了不施肥处理,氮磷钾配施和增施硼肥对青花菜养分吸收分配及产量和品质的影响。结果表明,现蕾期至花球膨大期,青花菜对氮、磷、钾的吸收量最大,整个生长期对钾的吸收最多,氮次之,磷最少。氮磷钾主要分配在叶片中,现蕾后逐渐向花球转移,从现蕾到采收时,叶片中氮、磷、钾分配率分别降低了19.6%、10%和9.0%,花球中氮磷钾分配率分别提高了23.1%、15.9%和11.1%。不施氮、磷、钾肥显著降低了花球产量、维生素C含量和成品率,增施硼肥处理的花球成品率较氮磷钾肥处理提高了4.8%,不施氮肥和钾硫肥(K₂SO₄)显著降低了花球中的硫代葡萄糖苷含量。相关性分析表明,青花菜产量与植株内氮、钾积累量显著正相关,成品率与植株内磷营养显著正相关。     

Principles for forcing tulips,hyacinths, daffodils,Easter lilies and Dutch irises

Systematic investigations on the forcing of tulips, hyacinths, daffodils, Easter lilies and Dutch iris have produced a fairly complete set of scientific principles. In this review, these principles have been classified into a 3-phase concept of forcing. These are: production, programming, and greenhouse. The production phase is defined as all processes which occur during bulb production and it terminates with the harvesting of the bulbs. The programming phase comprises all handling of the bulbs from harvesting until they are placed under greenhouse conditions. The greenhouse phase is the accelerated development of the bulbs until anthesis or marketing of the plants. These phases have been discussed relative to floral and root development and the basic environmental requirements of the bulb species.