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251.
Nitrogen Accumulation and Translocation for Winter Wheat under Different Irrigation Regimes 总被引:12,自引:0,他引:12
The translocation of pre‐anthesis nitrogen to the grain is an important source for winter wheat. The relation between the nitrogen translocation and irrigation regime was studied in the field under a rain‐proof trough shelter. Nitrogen (N) translocation amount, N translocation efficiency decreased with a decline in irrigation amount or by excessive irrigation. Compared with different organs, the leaf and stem had higher N translocation amounts, and contributions to grain for both cultivars – Jinan 17 and Lumai 21, indicating that stem also is a major N source for grain development. The contribution of pre‐anthesis total above ground N to grain N ranged from 57 to 76 %, indicating the importance of pre‐anthesis storage of N for achieving high grain N concentrations. Grain nitrogen and yield (kg ha?1) were positively and significantly correlated with the N translocation amounts and contributions, respectively, suggesting that the sink strength may be involved in the translocation of N from a vegetative organ to the grain. N harvest index (NHI) was significantly correlated with N translocation efficiency, suggesting that the latter is a prerequisite for increasing grain N and improving grain quality. The experiment showed that N translocation status is enhanced by better irrigation practices, but limited by severely deficient or excessive irrigation. 相似文献
252.
There are several strategies that can be applied in SNP discovery as for example the locus-specific amplification of target genome regions 《分子植物育种》2007,5(2):248-249
There are several strategies that can be applied in SNP discovery, as for example the locus-specific amplification of target genome regions (Primmer et al., 2002; Van et al., 2004) or simultaneous assembly of anonymous sequences which are the product of whole genome shotgun sequencing (Webber and Myers, 1997) or reduced representation shotgun sequencing (Altshuler et al., 2000). The majority of these methods are highly cost-prohibitive, however, and there is a necessity for development of new strategies that would be more suitable for small and medium-scale laboratories. 相似文献
253.
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
254.
This paper gives some analyses on the indoor climate and air quality in Chinese traditional quadral yard Buildings.A conclusion has been drawn that the living environment created by quadral yard building is of high quality.This kind of building is of great referential value in building human settlment environment with sustainable developmenlt and can also help to creat a better architectural form fitted in with the natural environment. 相似文献
255.
Y. B. Wang P. T. Wu X. N. Zhao J. L. Li L. Lv & H. B. Shao 《Journal of Agronomy and Crop Science》2010,196(1):55-65
The establishment of water-saving crop planning is an inevitable choice of the water-saving agriculture for the water-deficiency region in the arid and semiarid Loess Plateau of China and the world. The water-saving crop planning refers to the planting structure that centres the adjustment of the crop's adaptation to water, the optimization of temporal and spatial layout for crops, the local natural resources, marketing resources, human resources and financial input to enable region or basin with limited water resources to achieve the maximum economic, social and ecological benefits of planting industry under certain technology and economy. After the analysis on the research progress of optimization theory, optimization goals, optimization methods of water-saving cultivation structure and macro-control measures, it is pointed out that the main deficiencies of the current research of water-saving cultivation pattern optimization are lacking of a strong theoretical basis, and the immaturity of optimization technologies. The future crucial research direction will focus on five aspects such as the special optimization theory system, the division methods by studying the watershed unit and using 3S technology, optimization model based on multi-objective evolutionary algorithm, evaluation of rationality and macro-control measures on the basis of the public participation. 相似文献
256.
Starch Content and Granule Size Distribution in Grains of Wheat in Relation to Post-Anthesis Water Deficits 总被引:2,自引:0,他引:2
Post-anthesis soil moisture condition is closely associated with grain yield and quality in wheat ( Triticum aestivum L.). To investigate the effect of post-anthesis water deficit (WD) on starch content and granule size distribution, pot-experiments were conducted in 2006–2007 and 2007–2008 growing seasons, using five wheat cultivars with different amylose content. The result showed that the grain starch granules had a bimodal curve in the volume and surface area distribution, and a unimodal curve was found in number distribution. Post-anthesis WD reduced the B-granules (<10 μm in diameter) volume % and surface area % in Nuomai50206 and Gaocheng8901, increased the proportion in Weimai10, whereas the effect on those in Jinan17 and Shannong15 was not significant. Post-anthesis WD decreased the number % of <2 μm starch granules, significantly in all cultivars. The amylose content was negatively correlated with the volume of <10 μm and positively correlated to >15 μm starch granules, respectively, suggesting that small starch granules (<10 μm) are low in amylose content, whereas, big starch granules (>15 μm) are high. The results indicate that the grain starch granule size distributions of Jinan17 and Shannong15 with high amylose content were less affected by WD, than those of Nuomai50206 and Gaocheng8901 with low amylose content. 相似文献
257.
The genetic relationship between popping expansion volume and two yield components in popcorn using unconditional and conditional QTL analysis 总被引:2,自引:0,他引:2
Y. L. Li Y. B. Dong D. Q. Cui Y. Z. Wang Y. Y. Liu M. G. Wei X. H. Li 《Euphytica》2008,162(3):345-351
Popping expansion volume (PEV) is the most important quality trait in popcorn, while its germplasm is inferior to normal dent/flint
corn in yield. In this study, 259 F2:3 families, developed from the cross between a dent corn inbred Dan232 and a popcorn inbred N04, were evaluated for their PEV,
grain weight per plant (GWP) and 100-grain weight (100 GW) in two environments. The genetic relationship between PEV and GWP,
and 100 GW on individual gene loci were evaluated using unconditional and conditional QTL mapping methods. In total, five,
one and three unconditional QTL were identified for PEV, GWP, and 100 GW, respectively. The positive alleles of all QTL for
PEV were from N04, while positive alleles of all QTL for GWP and 100 GW were from Dan232. In conditional mapping, one and
two QTL failed to be detected, and all four additional QTL were detected. Nevertheless, three QTL were identified, which controlled
PEV independently from GWP/100 GW. They seemed to be potential candidates in popcorn breeding to increase PEV without decreasing
GWP/100 GW. The results suggested that for significantly correlated traits, the conditional QTL mapping method could be used
to dissect the genetic interrelationship between traits at the level of individual QTL, as well as reveal additional QTL that
were undetectable by unconditional mapping. 相似文献
258.
C.A. Liu S.L. Jin L.M. Zhou Y. Jia F.M. Li Y.C. Xiong X.G. Li 《European Journal of Agronomy》2009,31(4):241-249
This paper determined the effects of mulching time for double furrows and ridges using plastic film on soil water status, grain yield of maize, soil quality, and economic benefits. The study was conducted in a typical semiarid area during two growing seasons of 2006–2007 with the following three treatments: (i) plastic film mulching at maize sowing with conventional tillage, and the film was removed at harvest (CK); (ii) mulching applied 30 d before sowing with conventional tillage, and the film was removed at harvest (T1); and (iii) mulching at sowing with no-tillage, and the film left on the field after harvest in the first season and used for mulching in the second season (T2). The T1 in both years and T2 in the second year (2007) improved soil water content (in the 0–60 cm layer) and temperature (10 cm) at sowing compared with CK. After the two seasons, the soil water content was significantly higher in the 0–80 cm soil layer in CK and T1, and in the 0–120 cm soil layer in T2; however, it decreased significantly in 140–200 cm soil layer in CK and T1, compared to their initial values at sowing in April 2006, and there was no significant change in T2. The rainfall storage in the 0–200 cm soil layer during the non-growing season (late September 2006 to late April 2007) was 18.2 mm in CK, 34.0 mm in T1, and 59.7 mm in T2, and the rainfall storage in 100–200 cm soil layer was 16.5 and 18.6 mm higher in T2 than in CK and T1, respectively. In 2006, there were no significant differences in yield and water use efficiency (WUE) in all treatments. In 2007, the yield in T1 was significantly higher than in T2, but yields in T2 and CK were not significantly different, and there was no significant difference in WUE among treatments. Soil organic carbon (SOC) (0–20 cm) decreased in CK and T1, but increased (by 2.7%) in T2 at harvesting in September 2007 from the initial value of sowing in April 2006. The ratio of output to input was 1.32:1 for CK, 1.40:1 for T1, and 1.67:1 for T2 averaged across the two seasons. Therefore, T2 was a more sustainable model for increasing water storage, producing greater economic benefit and maintaining SOC balance for maize production in semiarid area. 相似文献
259.
甘肃省地处生态脆弱区,气候条件复杂,干旱发生概率高、范围广。为了更好地研究甘肃省干旱时空变化特征,综合考虑甘肃省气候类型和地理特征将其划分为4个气候分区(Ⅰ区,河西大陆性气候区;Ⅱ区,陇中北部季风气候区;Ⅲ区,陇南-陇中南部季风气候区;Ⅳ区,甘南高寒气候区),并采用甘肃省26个国家气象站点的气象资料,计算其近60年(1960—2019年)的月、季和年尺度的标准化降水蒸散指数(SPEI-1、SPEI-3、SPEI-12),结合气候倾向率、Mann-Kendall突变检验、空间插值等方法探讨甘肃省近60年的干旱时空演变特征。结果表明:从时间变化角度看,不同时间尺度的SPEI均呈减小变化趋势,且随时间尺度的增大,SPEI波动幅度越小;在四季变化上,春、夏、秋季SPEI在甘肃省各气候分区都呈现在波动中下降的趋势,且下降趋势明显,表明干旱趋势显著,冬季SPEI在各气候分区呈现在波动中上升的趋势,表明有湿润化的趋势。从空间变化角度看,甘肃省Ⅰ区呈干旱减缓趋势,Ⅱ区、Ⅲ区和Ⅳ区呈干旱加剧趋势,且春季各气候分区干旱加剧趋势明显,夏、秋季次之,而冬季基本上都呈现干旱减缓趋势;甘肃省不同气候分区不同等级干旱发生频率分布差异大且不均衡,干旱频率由小到大依次为:特旱、中旱、重旱、轻旱。 相似文献
260.
L.H. Wang X.H. Gu M.Y. Hua S.L. Mao Z.H. Zhang D.L. Peng X.F. Yun B.X. Zhang 《Scientia Horticulturae》2009
The root-knot nematodes (Meloidogyne spp.) are important nematode pests and cause serious diseases in pepper in the world. No molecular markers linked to the nematodes resistance N gene have been reported. In this paper, ‘Carolina Wonder’ (Capsicum annuum L.), a sweet pepper line resistant to root-knot nematode with N gene, ‘20080-5-29’ (C. annuum L.), an inbred line susceptible to root-knot nematode with good horticultural characteristics, and their F2 progeny with 320 individuals were used as materials. Evaluation of resistance and susceptibility of parental lines, F1 and F2 progeny inoculated with root-knot nematodes (Meloidogyne incognita) were carried out. ‘Bulked segregant analysis’ method was used to search for polymorphic markers from 512 pairs of AFLP primers. Based on the assessment of resistance and susceptibility and polymorphism of the AFLP marker in F2 population, the genetic linkage distance between the AFLP marker and the N gene was estimated. One AFLP marker E39/M41-339 was obtained and transferred to a SCAR marker amplifying a 315 bp DNA fragment linked to the N resistant allele and a 331 bp fragment linked to the N+ susceptible allele. The distance between the molecular marker and the nematodes resistance N gene is 6.3 cM. This research delivered a valuable tool for the marker assisted selection of nematodes resistance in pepper. 相似文献