不同早稻品种灌浆期高温胁迫后根系生理差异研究   总被引：8，自引：0，他引：8       下载免费PDF全文

李木英  石庆华  许锦彪  胡志红  谭雪明 《中国生态农业学报》2006,14(3):105-107

试验研究不同早稻品种灌浆期高温胁迫后根系生理差异结果表明,高温对不同水稻品种根系超氧化物歧化酶、过氧化物酶、过氧化氢酶活性均有影响,但对耐热型品种的影响显著小于热敏感品种,耐热型品种在高温胁迫后保护酶活性能较快恢复并接近对照水平;高温胁迫对耐热型水稻品种根系α-萘胺氧化力无影响,但热敏感品种根系氧化力明显下降,故根系α-萘胺氧化力可作为根系耐热指标之一。  相似文献   

Penetration resistance and root growth of oats in tilled and untilled loess soil     

W. Ehlers  U. Köpke  F. Hesse  W. Böhm 《Soil & Tillage Research》1983,3(3):261-275

Penetration resistance, bulk density, soil water content and root growth of oats were intensively studied in a tilled and an untilled grey brown podzolic loess soil. Bulk density and penetration resistance were higher in the top layer of the untilled soil compared with the tilled soil. In the latter, however, a traffic pan existed in the 25–30 cm soil layer which had higher bulk density and penetration resistance than any layer of the untilled soil. Above the traffic pan, rooting density (cm root length per cm³ of soil) was higher but below the pan it was lower than at the same depth in the untilled soil. Root growth was linearly related to penetration resistance. The limiting penetration resistance for root growth was 3.6 MPa in the tilled Ap-horizon but 4.6-5.1 MPa in the untilled Ap-horizon and in the subsoil of both tillage treatments. This difference in the soil strength-root growth relationship is explained by the build up of a continuous pore system in untilled soil, created by earthworms and the roots from preceding crops. These biopores, which occupy < 1% of the soil volume, can be utilized by roots of subsequent crops as passages of comparatively low soil strength. The channeling of bulk soil may counteract the possible root restricting effect of an increased soil strength which is frequently observed in the zero tillage system.  相似文献   

Improved method for determination of pectin degree of esterification by diffuse reflectance Fourier transform infrared spectroscopy   总被引：1，自引：0，他引：1  

Monsoor MA  Kalapathy U  Proctor A 《Journal of agricultural and food chemistry》2001,49(6):2756-2760

An improved method for the determination of pectin degree of esterification (DE) by diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) was developed. Pectin samples with a range of DE as determined by gas chromatography were used for developing a calibration curve by DRIFTS. A linear relationship between the DE of pectin standards and FTIR peak ratio for ester carboxyl peak area to total carboxyl peak area was found (R(2) = 0.97). Pectin DE of various samples was calculated from the linear fit equation developed by DRIFTS. Accuracy of the DRIFTS method was determined by comparing the DE values of four commercial pectins obtained by DRIFTS methods to the values obtained by the gas chromatography method. Greater precision was obtained for the FTIR measurement of test pectin samples when the ester peak ratio was used relative to the ester peak area.  相似文献   

Current status and future strategy in breeding grasspea (Lathyrus sativus)     

C. G. Campbell  R. B. Mehra  S. K. Agrawal  Y. Z. Chen  A. M. Abd El Moneim  H. I. T. Khawaja  C. R. Yadov  J. U. Tay  W. A. Araya 《Euphytica》1993,73(1-2):167-175

Efforts in grasspea (Lathyrus sativus) improvement have increased since the development of lines that are very low in the neurotoxin Beta-N-oxalyl-L-alpha-beta-diamino propionic acid (ODAP); also referred to as Beta-N oxalyl-amino-L-alanine (BOAA). Many programs now address several related aspects of improvement simultaneously. These include reduced ODAP concentrations, insect and disease resistance, nitrogen fixation, agronomic practices, fodder and forage production, and components for increased yielding ability. The coordinated, multidisciplinary approach now being applied to the genetic improvement of grasspea should allow the potential of this largely neglected grain legume to be fully realized.  相似文献   

Soil phosphorus status and turnover in central-European beech forest ecosystems with differing tree species diversity   总被引：1，自引：0，他引：1  

U. Talkner    M. Jansen  & F. O. Beese 《European Journal of Soil Science》2009,60(3):338-346

Problems in phosphorus (P) nutrition of forest trees raise questions concerning the soil P concentrations, pools and turnover in forests. In addition, it is not clear if, and to what extent, tree species diversity has an influence on the soil P status and turnover. The aim of this study was to investigate the P status and turnover in beech ( Fagus sylvatica L.) -dominated forest ecosystems on loess over limestone and to elucidate what role heterogeneities in tree species diversity would play. The soils of mixed species stands contained more organically bound P (710–772 kg ha⁻¹) than those of pure beech stands (378 kg ha⁻¹), whereas the inorganic P content differed little between the stand types. A large proportion (44–55%) of the total soil P was organically bound. This fraction was mainly dependent on the clay content of the soils and not on the tree diversity. The P input with leaf litter (1.4–2.1 kg ha⁻¹ year⁻¹) showed a tendency to increase with increasing diversity. The apparent P turnover times in the organic surface layers differed, with shorter turnover times in mixed species stands (2–3 years) than in pure beech stands (10 years). Possible explanations for the different turnover times were differences in the litter quality, interactions in mixed species litters and the soil pH and base saturation. Hence, the tree species mainly influence the apparent P turnover time in the organic surface layer, whereas the P concentrations and pools in the mineral soil are determined by the soil properties, particularly the clay content.  相似文献   

半干旱地区地膜覆盖、底墒和氮肥对春小麦根系生长的集成效应   总被引：2，自引：0，他引：2  

吕丽红  王俊  凌莉 《西北农林科技大学学报(自然科学版)》2003,31(3):102-106

在年降水量 4 1 5 m m的黄土高原中部黄绵土上 ,以春小麦 (Triticum aestivum)为供试作物进行大田试验 ,研究地膜覆盖 (设不覆膜、播种后覆膜 30 d、覆膜 6 0 d和全程覆膜 )、底墒 (设低、高 2种底墒 )和施氮 (设不施氮和施氮 75 kg/hm2 )对春小麦根系生长的影响。结果表明 ,覆膜后作物根系生长加快 ,中下层根系比例增加 ,有利于吸收土壤深层水分。相对发达的根系保证了作物吸收器官 (根 )和失水器官 (叶 )间的平衡 ,协调根冠间的干物质分配关系 ,能在不影响根系吸收能力的前提下 ,提高光合产物的繁殖分配比例。适时揭膜能够改善光合产物分配 ,促进根系生长下扎 ,维持生长后期活性。全程覆膜处理的表层和中层 (30～ 6 0 cm)土壤中 ,根系生物量显著低于其他处理 ,原因在于后期覆膜使土壤温度急剧升高 ,造成根系大量死亡和活性下降。因此及时揭膜 ,有利于作物生长后期的根冠比保持在较高水平 ,而全程覆膜对维持作物生长后期较高的根冠比不利  相似文献   

浅谈三亚酒店景观高差处理的设计方法     

苏志浩  周少开 《广东园林》2012,(1):48-54

酒店景观与其他景观相比有许多自身的特性,如私密性、舒适性、半开放式等。景观中用于处理高差的形式有许多,三亚酒店根据其建筑特色、周边环境、酒店风格等采用了独具特色的形式。良好的景观更容易让旅客获得优质的审美享受,增加旅游体验的愉悦感和深刻性。  相似文献   

Influence of crop establishment methods on yield,economics and water productivity of rice cultivars under upland and lowland production ecologies of Eastern Indo-Gangetic Plains     

Rishi Raj  Anil Kumar  I. S. Solanki  Shiva Dhar  Anchal Dass  Ashish Kumar Gupta  Vikash Kumar  C. B. Singh  R. K. Jat  U. C. Pandey 《Paddy and Water Environment》2017,15(4):861-877

A field study on assessment of crop establishment methods on yield, economics and water productivity of rice cultivars under upland and lowland production ecologies was conducted during wet seasons (June–November) of 2012 and 2013 in Eastern Indo-Gangetic Plains of India. The experiment was laid-out in a split-plot design (SPD) and replicated four times. The main-plot treatments included three crop establishment methods, viz. dry direct-seeded rice (DSR), system of rice intensification (SRI) and puddled transplanted rice (PTR). In sub-plots, five rice cultivars of different groups like aromatic (Improved Pusa Basmati 1 and Pusa Sugandh 5), inbreds (PNR 381 and Pusa 834) and hybrid (Arize 6444) were taken for their evaluations. These two sets of treatments were laid-out simultaneously in two production ecologies, upland and lowland during both years. In general, lowland ecology was found favourable for rice growth and yield and resulted in 13.2% higher grain yield as compared to upland ecology. Rice grown with SRI method produced 19.4 and 7.0% higher grain yield in 2012 and 20.6 and 7.1% higher in 2013, over DSR and PTR. However, PTR yielded 13.1 and 14.5% higher grain over DSR during 2012 and 2013, respectively. On an average, Arize 6444 produced 26.4, 26.9, 28.9 and 54.7% higher grain yield as compared to PS 5, P 834, PNR 381 and IPB1, respectively. Further, the interaction of production ecologies × crop establishment methods revealed that, in upland ecology, SRI recorded significantly higher grain yield as compared to PTR and DSR, but in lowland, grain yield resulting from SRI was similar to the yield obtained with PTR and significantly higher than DSR. The latter two methods (PTR and DSR) yielded alike in lowland ecology in both study years. The production ecologies × crop establishment methods × cultivars interaction on grain yield showed that the growing of Arize 6444 cultivar using SRI method in upland ecology resulted in the higher grain yield (8.87 t/ha). But the cost of production was also highest in SRI followed by PTR and DSR across production ecologies and cultivars. Cultivation of hybrid (Arize 6444) involved higher cost of production than all other cultivars. Irrespective of crop establishment methods and cultivars, gross returns, net returns and B:C ratio were significantly higher in lowland compared to upland ecology. Owing to higher grain yield, SRI method fetched significantly higher gross returns and net returns over PTR and DSR. Average increase in net return with Arize 6444 was 68.8, 41.0, 37.7 and 33.1% over IPB 1, PNR 381, P 834 and PS 5, respectively. There was a saving of 30.7% water in SRI and 19.9% in DSR over PTR under upland ecology. Similarly in lowland ecology, water saving of 30.2% was observed in SRI and 21.2% in DSR over PTR. Due to higher yield and saving on water, SRI returned significantly higher total water productivity (TWP) (5.9 kg/ha-mm) as compared to DSR (3.5 kg/ha-mm) and PTR (3.6 kg/ha-mm) under upland ecology. In lowland ecology, also SRI (6.2 kg/ha-mm) resulted in higher TWP as compared to other two methods. However, DSR gave significantly higher TWP as compared to PTR. Among cultivars, hybrid Arize 6444 recorded the highest TWP in both upland and lowland production ecologies across crop establishment methods. Hence, growing of hybrid Arize 6444 with SRI method can enhance rice productivity and water-use efficiency in lowland and upland production ecologies of Eastern Indo-Gangetic Plains and in other similar regions.  相似文献   

Die Wiederbewaldung der Gebirge in Fransreich     

U. 《European Journal of Forest Research》1865,9(1):41-53

Ohne Zusammenfassung  相似文献   

QSA的mRNA在人和小鼠各组织中表达规律     

徐雯雯  徐汪节  朱子珏  王朝霞  乔中东 《上海交通大学学报(农业科学版)》2011,29(5):25-29

从基因水平上检测精子中新基因QSA的表达规律及时空分布,并推测其可能的生物学作用.采用RT-PCR和原位杂交法检测QSA在人和小鼠多种组织中的表达.RT-PCR结果显示QSA在小鼠的睾丸、精子和受精卵中特异性表达,而在小鼠卵细胞、囊胚等组织中未检测到该基因的mRNA.原位杂交结果表明QSA在人的部分腺体组织(如:睾丸、...  相似文献