A gene for hybrid necrosis in an inbred line of rye (Secale cereale L.)

Summary An inbred line of rye (Secale cereale L.) has been found to carry a gene for hybrid necrosis. This gene was detected in crosses with a highly crossable wheat (Triticum aestivum L.) genotype which carries the gene Ne₂. This appears to be the first report of a gene for hybrid necrosis being present in the rye genome.     

Effekte der Sorten- (Weizen)und der Arten- (Weizen, Roggen) Mischung auf die Ertragsleistung krankheitsfreier Bestände

Effects of cultivar (wheat) and species (wheat, rye) mixtures on grain yield of desease-free stands
Cultivar mixtures (winter wheat) and species mixtures (winter wheat/winter rye) grown free from pests and diseases in different environments are compared to pure stands and analyzed with respect to inter-component relationships relevant for yield. All mixtures consisted from two components which were planted 1:1. Mixing effects (i.e. deviations from arithmetic mean of respective components grown in pure stands) on grain yield/ha and yield structure were dependent on components and growing conditions, particularly nitrogen availability. Under conditions suboptimal for one component, ontogenetic differences between components resulted in positive mixing effects on grain yield since the yield proportion of the accompanying partner increased more than proportionally. In several instances, yield proportions shitted without leading to mixing effects. In some experiments and/or mixtures mixing effects could not be observed at all.     

Einfluß eines variierten N-Angebots auf α-Amylase-Aktivität, primäre Dormanz und Auswuchsresistenz von Weichweizen (Triticum aestivum L.), Roggen (Secale cereale L.) und Triticale (X Triticosecale Wittmack)

Influence of Varying N-Fertilization Rates on α-Amylase Activity, Primary Dormancy and Resistance to Pre-Harvest Sprouting in Wheat ( Triticum aestivum L.), Rye ( Secale cereale L.) and Triticale (X Triticosecale Wittmack)
Pre-harvest sprouting, induced by unfavourable ecological conditions, can affect the grain growers success considerably. Positive correlations are reported between resistance to pre-harvest sprouting and primary dormancy. Genotypes with a short dormancy period have a high pre-harvest sprouting risk. In the case of a premature germination of caryopses in the head of grain a hydrolysis of intact starch granules caused by the endoenzyme α-amylase takes place in the endosperm.
Negative correlations between falling number and protein content are reported, however, it is unknown, if a varying N-application influences pre-harvest sprouting rates, dormancy periods and amylase activity. For this reason, both greenhouse and field trials were conducted with different N-fertilization rates and (additional in the greenhouse) a rain simulation treatment.
High amounts of α-amylase a few days post anthesis are opposed to small enzyme activities in mature kernels. Stratificating temperatures and germination inducing precipitations at the same time are inducing pre-harvest sprouting and a high α-amylase activity especially in rye and triticale. It seems as if N-deficiency reduces the possibility of pre-harvest sprouting, on the other hand high N-rates increase the enzymes' activity and promote germination processes in the kernel. Effects of N-fertilization on dormancy are not known.
In the discussion of reasons for an increase of α-amylase activity in sprouted grain caryopses, changes in the relation of the phytohormones gibberellic acid (promoter of enzyme activities) and abscisine acid are mainly presumed.     

广东省阳山县秋季蒸发量演变及对当地秋旱的影响

利用阳山县气象观测站1957～2008年阳山县秋季水分蒸发量的气象观测资料,分析了阳山县秋季水分蒸发量的演变规律以及影响蒸发量的气象要素,以此研究蒸发量对阳山县秋旱的影响。结果表明：热力作用对阳山秋季蒸发量影响最大,动力作用次之;气象要素中,对秋季蒸发量影响较大的是平均气温、平均最高气温、平均日较差和日照,风速的影响次之。用气象观测的蒸发量作为实际蒸发量的表征,评估了气候干湿的变化及对当地秋旱的可能影响。运用干燥度,定量地讨论了蒸发量对秋旱的影响。     

中稻-秋马铃薯模式效益与关键技术

中稻收获后有一段时间适宜的温光资源.如何利用这段有利的温光条件进行农业生产技术或模式创新是值得挖掘和探讨的课题.每年9～11月,中稻收获后,当阳市温度由高至低变化.根据秋马铃薯生长发育特点,该时期气候、温度、土壤等各方面条件非常适宜马铃薯的生长和种植.在种植结构调整中,开展秋马铃薯和中稻配茬种植模式,既能充分利用中稻收获后一段时期的温光资源,又能充分发挥马铃薯的生产和市场优势,获得较高的效益.     

红壤旱地肥料配施对秋芝麻生长发育和产量的影响

为了探讨红壤旱地秋芝麻的需肥规律,开展了不同氮磷钾肥料配比试验,结果表明:红壤旱地肥料配施以N∶P2O5∶K2O=6∶4∶6对秋芝麻产量构成有利,且有机肥与无机肥配施有利于秋芝麻蒴果及籽粒的形成,进而提高秋芝麻的产量。另外,施用生物有机肥对秋芝麻能起到一定的防病效果。     

郴州秋季连阴雨天气过程气候特征与预报

利用郴州市1981 ～ 2010年的气候观测资料,按照定义秋季(9月21日～1l月20日)连阴雨天气过程的条件进行相应的资料处理,统计出每一次连阴雨天气过程,并对发生的每一次连阴雨天气过程的天气背景进行分类统计分析.结果表明,郴州各县市区连续3d以上的秋雨次数分布呈现中部地区多、南部地区少,10月上旬和11月中旬是秋雨过程的多发期.郴州秋季连阴雨天气的形成,其大气环流形势和季节性转换基本一致,其中地面冷空气入侵影响郴州是秋季连阴雨开始的主要特征;与长波槽系统的稳定维持有着密切的关系,沿海槽的建立是郴州秋季连阴雨天气结束的主要特征,长波槽系统的稳定决定秋雨的长短.总结郴州秋季连阴雨天气过程的变化特征,有助于提高对郴州秋季连阴雨天气过程的预测预报水平,提升为农气象服务水平.     

秋种马铃薯高产栽培技术

经过多年多点示范,总结出高山秋种马铃薯高产栽培技术。即秋种马铃薯以选择排灌水方便的沙壤土或黄壤土为宜,忌与茄科作物连作;8月上中旬,采用单垄双行双三角形播种,密度5.25万~6.00万株/hm2;合理施肥,注意防治病虫害。     

南宫山国家森林公园秋色叶树种资源调查研究

对陕西省岚皋县南宫山国家森林公园秋色叶树种资源进行全面调查整理,得出南官山国家森林公园秋色叶树种共计22科32属36种.并对秋色叶树种的开发利用及保护进行了探讨.     

Nitrogen and winter cover crop effects on spring and summer nutrient uptake

Overseeded winter annuals in bermudagrass [Cynodon dactylon (L.) Pers.] improve annual dry‐matter (DM) yield and capture nutrients in fields receiving manure application. This study determined the DM and nutrient uptake responses of annual ryegrass (Lolium multiflorum L.), cereal rye (Secale cereale), berseem clover (Trifolium alexandrinum L.) and bermudagrass‐winter fallow to 0, 50, 100 and 150 kg N ha^?1 applied approximately 2 months before a single spring harvest, and in addition to swine‐effluent N (258 and 533 kg ha^?1 in summer 2000 and 2001, respectively). Under drought conditions in 2000, DM yield at the spring harvest was highest in ryegrass, and summer DM yield of bermudagrass was greater at 100 and 150 kg N ha^?1 than 50 kg N ha^?1(P < 0·05). The concentration and uptake of N at the spring harvest increased linearly across N rates in both years (P < 0.05). Cover crops differed in N uptake in 2000 (P < 0.01) and values ranged from approximately 141 kg N ha^?1 in berseem clover to 86 kg N ha^?1 in rye. Per unit of N applied, uptake of N increased by approximately 0·409 kg ha^?1 in 2000 and 0·267 kg ha^?1 in 2001; uptake of P increased by 0·029 and 0·014 kg ha^?1 respectively. In 2000, uptake of P was responsive to N rate and this relationship was significant (P < 0·01) in winter fallow (slope = 0·032) and ryegrass (slope = 0·057). Increased uptake of N and P at the single spring harvest was due mainly to higher concentrations in herbage and not higher DM yield.