共查询到20条相似文献，搜索用时 78 毫秒
1.
在乡村振兴这一国家战略背景下，果树资源育种工作者和研究生导师，必须坚持将产业问题转化为科学问题、理论创新与技术创新并重、良种与良法配套及以科研促教学培养创新人才；并坚持面向世界科技前沿、面向经济主战场、面向国家重大需求和面向人民生命健康；把水果盘子牢牢端在中国人手中是国家重大战略需求，即不依赖进口的国内果品生产与市场销售的内循环来满足14亿中国人优质水果的周年供应需求，推动农民增收和乡村振兴，苹果、柑橘、梨、桃和葡萄等大宗水果是主角；根据中国国情和果实特性，需要培育优质、耐贮、晚熟的苹果和梨主栽品种，以及早、中、晚熟期配套的桃、柑橘和葡萄品种；根据果树育种技术发展现状，杂交育种与芽变选种有机结合是解决果树品种问题、培育国家重大需求品种的有效技术途径。 相似文献
2.
3.
4.
5.
6.
“医食同源,吃营养,吃健康”已经成为人们的共识。针对我国苹果产业品种单一、特色多样化品种严重不足、主栽品种’红富士'果实着色、风味品质及结果习性等性状需要进一步改良、苹果育种特别是红肉苹果育种周期长、缺乏优异种质等问题,系统介绍了以“高类黄酮(红皮与红肉)”为主线,以新疆红肉苹果挖掘与创新利用为研究重点,在品质形成与芽变机理、红肉苹果优异种质创制、高效育种技术创建、特色多样化新品种培育及其配套高效栽培技术创新等方面取得的最新研究进展及其成果,旨在为其他野生果树资源的评价挖掘与创新利用提供参考。 相似文献
7.
中国栽培面积66.67万hm2以上的落叶果树有苹果、梨、桃和葡萄4种，针对这些重要果树果实品质和熟期，国内几代遗传育种工作者经过几十年的协同创新和联合攻关，在优异种质评价挖掘与创制的基础上，创建了优质高效育种技术体系，育成了优质、耐贮、不同熟期、特色多样的苹果和梨系列优质新品种，育成了桃和葡萄早、中、晚熟期配套优质新品种；研发了新品种优质高效配套栽培技术体系，推动了自主研发新品种的大面积推广应用及产业优质高效发展，为保障优质水果的周年需求提供了重要支撑。 相似文献
8.
9.
宁夏果树种质资源保存与利用宁夏果树资源共有２５个属、７５个种、８３２份。其中，苹果２８２份、梨１１７份、葡萄２３８份、桃１０４份、李３４份、杏６７份。（１）种质资源引种保存我所果树品种资源圃面积７．８ｈｍ２，共保存６个树种，苹果（１６０个）、梨（１０... 相似文献
10.
建国以来,尤其改革开放的２０年来,我国果树科技人员坚持科研与生产相结合,试验、示范与推广相结合,实验室和农村基点相结合,广泛开展科学实验,果树科研取得了很大成绩与进展。１ 种质资源搜集与鉴定 （１）建立国家种质资源圃 在组织全国果树资源普查、搜集的基础上,建成了苹果、梨、柑桔、葡萄、龙眼等果树１９个树种１６个国家果树种质资源圃,圃地总面积１２３．５ｈｍ２,保存种质资源１０００３份。苹果、梨、葡萄等果树茎尖试管保存和超低温保存研究取得了可喜成绩。 （２）果树资源性状鉴定与评价 通过对果树１９个… 相似文献
11.
Robert Rosen 《Landscape Ecology》1989,3(3-4):207-216
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. 相似文献
12.
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. 相似文献
13.
Wetlands, carbon, and climate change 总被引：3，自引：0，他引：3
William J. Mitsch Blanca Bernal Amanda M. Nahlik Ülo Mander Li Zhang Christopher J. Anderson Sven E. Jørgensen Hans Brix 《Landscape Ecology》2013,28(4):583-597
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. 相似文献
14.
Ralph E. J. Boerner 《Landscape Ecology》2012,27(8):1235-1236
15.
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 总被引：4，自引：0，他引：4
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。 相似文献
16.
This paper is based on interviews with fifteen professionals within ecology, forestry and park and landscape architecture. The interviewees are believed to have had a large influence on woodland planning in Sweden between 1950 and 2000. They have won recognition because of their ability to transform theoretical knowledge into practical action. Their work is translating theory into practice and, as such, it may be regarded as art in its deepest sense. During a long period the educational system as well as the dominating research has been concentrating on providing better facts in a search for the best knowledge, high degrees of generality and objectivity. However, this may cause many disadvantages. It has lead to a standardisation and an oversimplification of knowledge and thereby also to an oversimplification of the landscape. This study is based on a humanistic approach, on theory of knowledge, of how facts coming from the world of natural sciences can be encapsulated in daily woodland management. 相似文献
17.
Landscape Ecology, Cross-disciplinarity, and Sustainability Science 总被引：6，自引：16，他引：6
Jianguo Wu 《Landscape Ecology》2006,21(1):1-4
18.
19.
Richard E. Toth 《Landscape Ecology》1988,1(4):193-201
A soft paradigm for landscape analysis is presented. This paradigm focuses on the analysis of function first, and then on structure. The objective is to determine which factors are operationally significant, how these factors bring about change, and how they define the spatial characteristics of landscapes. 相似文献
20.
Road Density and Landscape Pattern in Relation to Housing Density,and Ownership,Land Cover,and Soils 总被引：5，自引：0，他引：5
Roads are conspicuous components of landscapes and play a substantial role in defining landscape pattern. Previous studies
have demonstrated the link between roads and their effects on ecological processes and landscape patterns. Less understood
is the placement of roads, and hence the patterns imposed by roads on the landscape in relation to factors describing land
use, land cover, and environmental heterogeneity. Our hypothesis was that variation in road density and landscape patterns
created by roads can be explained in relation to variables describing land use, land cover, and environmental factors. We
examined both road density and landscape patterns created by roads in relation to suitability of soil substrate as road subgrade,
land cover, lake area and perimeter, land ownership, and housing density across 19 predominantly forested counties in northern
Wisconsin, USA. Generalized least squares regression models showed that housing density and soils with excellent suitability
for road subgrade were positively related to road density while wetland area was negatively related. These relationships were
consistent across models for different road types. Landscape indices showed greater fragmentation by roads in areas with higher
housing density, and agriculture, grassland, and coniferous forest area, but less fragmentation with higher deciduous forest,
mixed forest, wetland, and lake area. These relationships provide insight into the complex relationships among social, institutional,
and environmental factors that influence where roads occur on the landscape. Our results are important for understanding the
impacts of roads on ecosystems and planning for their protection in the face of continued development. 相似文献