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空气湿度对澳洲坚果授粉受精能力和生理特性的影响 总被引：10，自引：4，他引：10
花期澳洲坚果植株经不同空气湿度处理结果表明,在低空气湿度条件下,植株的花粉育性降低、SOD活性降低、POD活性上升、座果率及光合产物（叶绿素含量、总糖含量和淀粉含量）下降、幼果生长速度减慢;空气湿度降低导致酶活性降低,自由基含量增加,生物膜功能受损,生理代谢紊乱,结果造成叶片光合作用能力下降,干物质积累少,生物产量降低,花粉萌发率低、花粉管生长速度慢,造成花期不遇、授粉受精不良、座果率低,最后造成产量降低。不同品种受主气湿度胁迫的影响程度不一样,品种的内部生理特性、花粉育性以及产量都存在差异。3个品种的耐早性为HAES900 >Makai>Keauhou。较高的空气湿度有利于澳洲坚果的生长发育。 相似文献
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不同抗旱措施对东试早柚光合生理特性及产量的影响 总被引：1，自引：0，他引：1
以东试早柚为试材,采用常规管理为对照,开展黑地膜、白地膜、杂草覆盖和添加保水剂措施的田间比较试验,研究不同抗旱措施对柚子物候期光合生理特性及其产量的影响。结果表明,柚子各物候期叶片的净光合速率（Pn）、蒸腾速率（Tr）和气孔导度（Gs）均以黑地膜和白地膜处理最高,其次为草覆盖和保水剂处理,对照表现为最低。各抗旱措施柚子叶片的水分利用效率（WUE）均高于对照,从柚子现蕾期（1月）至壮果期（6月）以草覆盖和保水剂处理的WUE最高,而在柚子成熟期（7~9月）以黑地膜处理的WUE最高,对照的WUE表现最低。总的看来,不同抗旱措施均明显提高了全物候期柚子叶片的Pn及WUE;各抗旱措施处理以黑地膜处理的座果率和产量较对照均增加最为显著,较对照分别提高了91.7％和56.9％,白地膜和草覆盖的座果率及保水剂处理的产量居中,分别较对照提高了29％和47％、36.5％和31.9％,而对照的座果率与产量均最低。各抗旱措施效果从高到低依次为：黑地膜>白地膜>草覆盖>保水剂>对照。 相似文献
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澳洲坚果授粉试验及花粉管生长的荧光显微观察 总被引：1，自引：0，他引：1
澳洲坚果品种HAES900的授粉试验及花粉管生长的荧光显微观察表明:HAES900×D4、HAES900×HAES695、HAES900×HAES900平均每个花序的最终座果率分别为0.56%、0.25%、0.12%,异花授粉的最终座果率比自花授粉的高出108%～367%,说明品种HAES900的异交亲和性好于自交亲和性;HAES900自花授粉的20个花序中,最终仅有20%的花序结实,说明品种HAES900可能具有部分自交不亲和性;澳洲坚果授粉后6h柱头上花粉大量萌发;异花授粉花柱基部的花粉管数量是自花授粉的2.5倍。 相似文献
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不同覆盖和播种方式对渭北旱地小麦产量及土壤水分的影响 总被引：10，自引：1，他引：9
为了筛选适应旱地小麦的高产覆盖和播种方式,在渭北黄土高原区,通过田间试验,研究了平膜穴播(S1)、秸秆覆盖条播(S2)、垄上覆膜穴播沟中覆草(S3)、垄上覆膜沟内条播覆草(S4)、露地条播(S5)五种处理方式对旱地土壤水分及冬小麦产量的影响。结果表明,S1、S3和S4三种处理具有显著的保水与增产效果,S2的保水效果不明显,但也有一定的增产作用;S1、S3和S4的保墒作用主要在小麦生育前期:越冬期100cm内各土层的土壤含水量均明显高于对照(露地条播),返青期0~60cm土层的土壤含水量明显高于对照,拔节期0~40cm土层的土壤含水量明显高于对照;在小麦生育后期,S1、S2、S3和S4的保墒作用均不明显。S1、S2、S3和S4四种处理的籽粒产量分别高出对照(露地条播)56.8%、14.7%、43.5%和47.5%。 相似文献
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澳洲坚果幼苗对缺水胁迫及复水的适应性反应 总被引：2，自引：0，他引：2
以澳洲坚果幼苗为试材,探讨缺水胁迫及复水处理后,其叶面积、叶片可溶性糖含量的适应性变化.结果表明:与对照相比,水分亏缺处理期间澳洲坚果叶面积呈降低趋势,可溶性总糖、还原性糖、蔗糖含量呈上升趋势;复水后,叶面积有较大的反弹,产生显著的补偿效应,而叶片可溶性总糖、还原性糖、蔗糖含量急剧下降,产生显著的负补偿效应.在西双版纳特有的旱季与雨季区别明显,饱和土壤水分处理(对照)的澳洲坚果幼苗在复水前后叶面积和叶片可溶性总糖、还原性糖、蔗糖含量同样也表现为先降后升、先升后降. 相似文献
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《作物研究》2017,(4)
2015年在甘肃省张掖市开展了不同地膜覆盖方式(覆白膜、覆黑膜、不覆盖)与灌水定额(每次450、900、1350、1800 m3/hm~2,共4次)对甜高粱产量和糖度影响的研究,旨在寻求最佳的覆膜方式和灌水量,为河西地区种植甜高粱节水增效提供理论和科学依据。结果表明:覆膜和灌水量对甜高粱产量和糖度影响显著,不同覆膜方式在灌水定额1350 m3/hm~2处理下,甜高粱产量较高,尤其在覆黑膜且灌水定额1350 m~3/hm~2处理下,甜高粱产量达到9.82 t/hm~2,显著高于覆白膜和不覆盖条件下同等灌水量处理;3种覆膜方式都以灌水定额900 m3/hm~2处理下糖度最高。综合分析认为,覆黑膜并采用900、1350 m~3/hm~2的灌水定额,可作为提高甜高粱糖度和产量的主要技术措施。 相似文献
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基于云南热区澳洲坚果种植区季节性干旱及先天性低有效磷的土壤特征,探讨丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)接种对具有排根的引种作物-澳洲坚果幼苗磷利用的影响,为外来物种的本地驯化栽培提供理论依据。在正常水分与水分胁迫条件下,对盆栽的澳洲坚果幼苗分别接种土著丛枝菌根真菌(native arbuscular mycorrhizal fungi)和摩西球囊霉(Glomus mosseae),测定接种不同AMF对澳洲坚果幼苗生长、菌根定殖、酸性磷酸酶活性、柠檬酸分泌及磷素吸收等的影响。结果表明,接种土著AMF(N-AM)处理对澳洲坚果幼苗排根或非排根的侵染率显著高于接种摩西球囊霉(G-AM)处理,正常水分条件下N-AM处理的侵染率最高;两种水分条件下,接种AMF的植株地上部和地下部干重更高,正常水分处理下达到最大。菌根侵染率与排根产生量之间显著正相关,水分胁迫显著抑制了植株的排根产生量;与不接种相比,接种处理能显著提高排根产生量。接种AMF后根系对磷素的活化、吸收及转化能力显著升高,表现为接种的澳洲坚果幼苗根系、茎秆和叶片中全磷含量较高,两种水分条件下均表现为N-AM>G-AM>CK;菌根与排根相互协调共同发挥作用,显著改善了澳洲坚果幼苗根系对磷素的活化和吸收能力,且菌根比排根发挥了更大作用,尤其在水分胁迫条件下。两种AMF均能与澳洲坚果幼苗建立共生关系,N-AM处理的幼苗各指标显著优于G-AM处理,可能是由于拥有多样性优势的土著AMF在澳洲坚果幼苗根系中定殖能力较强或是AMF真菌对外来物种澳洲坚果有正反馈作用。 相似文献
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Potato growth with and without plastic mulch in two typical regions of Northern China 总被引：2，自引：0，他引：2
Plastic film mulching is an important agricultural practice to save water and improve crop productivity in Northern China. Three field experiments were conducted to examine the effect of plastic mulch on soil temperature, potato (Solanum tuberosum L.) growth and evapotranspiration under drip irrigation in two typical regions of Northern China in 2001 and 2006. Results suggest that daily mean soil temperature under mulch was 2–9 °C higher than without mulch, especially during the early growth. Potato growth was restrained under mulching conditions in the North China Plain mainly due to the higher air temperature in this region and thus the higher soil temperature. The negative effects of mulching included a lower emergence and fewer marketable tubers per plant. Evapotranspiration and potato tuber yield were both reduced by mulch, especially in the North China Plain. In northwest China, mulch favorably increased the weight of jumbo tubers (W ≥ 300 g) per plant. Mulching duration had little effect on potato evapotranspiration in northwest China. However, both tuber yield and water use efficiency (WUE) decreased with increases in mulch duration, which suggests the plastic mulch should be removed early. 相似文献
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In a replicated field experiment carried out in Northern Ireland in 1998, the effects of sowing date (17 April, 5 May, 19 May and 1 June), cultivar of forage maize (Hudson and Diamant) and treatments with no mulch (NP), total cover plastic mulch (TC), TC plastic mulch removed at eight‐leaf growth stage (EL) and punch plastic mulch (PU) on the rate of development of the crop and the accumulation of dry matter (DM) in the whole plant and cobs were described. Soil and air temperatures under the mulch treatments and in the open were recorded and the daily accumulation of Ontario heat units (OUs) calculated for each treatment based on the air temperatures experienced by the crop for the periods that it was under plastic mulch and in the open. The interval from sowing to emergence was proportional to the accumulated heat units above a soil base temperature of 8·2°C. The phenology of leaf emergence varied widely in terms of calendar date across the sowing date and plastic mulch treatments but relative to adjusted OUs the treatments were more closely aligned. Treatment PU advanced the crop less than the other mulch treatments relative to calendar date but, relative to OUs, more than these treatments. Physical damage to plants emerging through the TC treatment and air temperatures exceeding 40°C during the first month under treatments TC and EL did not appear to retard physiological development. The total adjusted OUs to reach 50% silking ranged from 1432 to 1753. Close relationships were found between the total OUs from silking to harvest and the whole crop DM content, cob DM content, cob yield and starch concentration of the whole crop at harvest so that differences between the treatments could largely be accounted for by the differences in silking date. It was concluded that the OU system can provide a reasonable model of maize growth for crops sown under TC plastic mulch providing air temperatures under the plastic are used for the period that the crop experiences them. However, the OU system is less reliable for crops grown under punch plastic because of the soil warming effect of the mulch that is not taken into account by the OU system. 相似文献
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The expansion of maize (Zea mays) into cooler areas has been facilitated by the availability of early maturing cultivars and by cultivation under plastic mulch. However, year‐to‐year variation in harvest quality remains a problem. The yield and quality of ‘Goldcob’, an early maturing forage maize, were assessed over 5 years from plots grown in the open and under plastic mulch. For both treatments, there was significant between‐year variation in yield and quality (starch content, metabolizable energy, organic matter and D‐value), and starch content was particularly variable. The use of plastic mulch to warm the soil advanced the establishment of the crop, with silking occurring on average 19 days earlier. This resulted in significantly higher yields under plastic mulch, with a mean increase of 3·9 t ha?1. The plastic mulch also resulted in significant increases in quality parameters, with starch content showing a mean increase of 36%. The Ontario heat unit model explained much of the variability in yield, both in the open and under plastic mulch. Plastic mulch had no consistent effect on Ontario heat units accumulated prior to silking, but Ontario heat units accumulated between silking and harvest (OHUpost‐silk) were found to be an adequate predictor of yield. The response of starch content was more complex, showing a clear plateau in the response to temperature at 1200 OHUpost‐silk, above which the accumulation of starch appears limited by other factors. 相似文献
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Chemical soil disinfestation often leads to the eradication of most microbial residents. This creates a microbial vacuum, which often leads to a rebounding of pathogens. This in turn may cause even more damage than those originally targeted for control. Soils, especially those with low microbial populations are more vulnerable to pathogen reinvasion following fumigation. A non-chemical approach to improve the control of soilborne pests involves combining organic amendments with soil solarization. Heating soils, that have been covered with plastic film and amended with suitable organic materials, actuates a chain reaction of chemical and microbial degradation, which leads to the generation of toxic compounds in vapor and liquid phases in the soil. The generation of toxic compounds increases with temperature. These compounds accumulate under the plastic mulch, and enhance toxicity against soil flora and fauna, especially soilborne plant pathogens. The plastic mulch traps the volatile compounds and creates an atmosphere in the soil that enhances degradation of the organic matter. The toxicity of the generated volatile compounds is expected to be higher at the high soil temperature prevailing during solarization. At the end of the process, the soil contains less pathogens, and different microflora, which may suppress reestablishment of pathogens in the soil. The effect of solarizing organically amended soil as a control method was validated under commercial field conditions. A long-term effect of the combined treatments was also evident. 相似文献
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Effectiveness of UV reflective plastic mulch for the management of silverleaf whitefly (Bemisia argentifolii Bellows and Perring) was evaluated in selected cucurbits. The reflective mulch repelled silverleaf whitefly adults in pumpkin (Cucurbita maxima Duchesne), cucumber (Cucumis sativus L.) and zucchini squash (Cucurbita pepo L.). Reduced colonization by B. argentifolii adults resulted in reduced populations of nymphs and a delay and reduction in the incidence of silverleaf in pumpkin and zucchini squash. Reflective mulch was as effective in reducing nymphal B. argentifolii populations as was a pre-plant soil application of imidacloprid. Zucchini squash, pumpkin and cucumber yields were significantly higher in plants grown over reflective mulch than in those grown over unmulched soil. Zucchini squash yields from plants grown over reflective mulch also were higher than from plants grown in plots receiving a pre-plant application of imidacloprid. This study confirmed that UV reflective plastic mulch can be used to manage B. argentifolii and the mulches give protection equal to that provided by imidacloprid. 相似文献
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Two field studies were conducted in the San Joaquin Valley (SJV) of California in order to describe the association of arthropods and possible virus diseases with the plant canopy of early-season, bush-trained, fresh-market tomato (Lycopersicon esculentum L. cv. Shady Lady) over three soil surface microenvironments. The experimental treatments were based on alterations to planting bed surfaces, as follow: 1) soil covered with silver metalized, light-reflective plastic mulch; 2) soil covered with biological mulch consisting of killed, chopped, cool-season cover crop residues [mixture of triticale (X Triticosecale Wittm.), rye (Secale cereale L. cv. Merced), and common vetch (Vicia sativa L.)]; or 3) bare soil (not covered) – the SJV standard tomato production practice. In both studies, the predominant arthropods encountered in all treatments were the aphid species Aphis craccivora Koch, Macrosiphum euphorbiae Thomas, and Myzus persicae Sulzer; the western flower thrips (Frankliniella occidentalis Pergande), and the false chinch bug (Nysius raphanus Howard). These are all considered to be pests of cultivated tomato plants. Spiders were the most prevalent arthropod predator group recovered from foliage samples. All monitored arthropods, except spiders, were most abundant in tomato plants grown over the conventional, bare soil surface, and least abundant (P < 0.05) in plants grown over the silver plastic mulch. Spider numbers were highest in plant foliage over the biological mulch. Other arthropods commonly found on tomato plants in the SJV, including leafhoppers, whiteflies, various caterpillars, and predaceous taxa, were not commonly nor consistently encountered. This was likely due to the early-season timeframe of these studies. Similarly, foliar virus disease symptoms, which were originally targeted for monitoring, were virtually nonexistent. The only arthropod pest species encountered which consistently caused economically important damage to tomato fruit was N. raphanus. In both experiments, tomato fruits grown over the reflective plastic mulch had significantly less (69.5% and 39.7%, respectively) damage due to this pest than those over bare soil. The biological mulch gave inconsistent, intermediate damage reductions. Results from these two field studies showed that reflective plastic bed mulch suppressed populations of a variety of tomato canopy-associated arthropod taxa in early-season plantings, as compared to conventional, bare-soil beds. The biological bed mulch results were more inconsistent, but gave indications that killed cover crop residues, as well as the light-reflective plastic, may be of value in integrated pest management programs for fresh-market tomato production. 相似文献