Nutrient deficiency limits population development,yield formation,and nutrient uptake of direct sown winter oilseed rape

Direct-sowing establishment method has great significance in improving winter oilseed rape（Brassica napus L.） production and guaranteeing edible oil security in China. However, nutrient responses on direct sown winter oilseed rape（DOR） performance and population development dynamic are still not well understood. Therefore, five on-farm experiments were conducted in the reaches of the Yangtze River（RYR） to determine the effects of nitrogen（N）, phosphorus（P）, and potassium（K） deficiencies on population density, dry matter production, nutrient uptake, seed yield, and yield components of DOR plants. Four fertilization treatments included the balanced NPK application treatment（NPK, 180 kg N, 39.3 kg P, 100 kg K, and 1.8 kg borax ha–1） and three nutrient deficiency treatments based on the NPK treatment, i.e., –N, –P, and –K. The results indicated that DOR population density declined gradually throughout the growing season, especially at over-wintering and pod-development stages. Nutrient deficiency decreased nutrient concentration in DOR plants, limited dry matter production and nutrient uptake, and thereby exacerbated density reduction during plants growth. The poor individual growth and reduced population density together decreased seed yield in the nutrient deficiency treatment. Averaged across all the experiments, seed yield reduced 61% by N deficiency, 38.3% by P deficiency, and 14.4% by K deficiency. The negative effects of nutrient deficiency on DOR performances followed the order of –N–P–K, and the effects were various among different nutrient deficiencies. Although N deficiency improved DOR emergence, but it seriously limited dry matter production and nutrient uptake, which in turn led to substantial plants death and therefore resulted in a very low harvested density. The P deficiency significantly reduced initial density, limited plants growth, and exacerbated density reduction. The K deficiency mainly decreased individual growth and yield, but did not affect density dynamic. Our results highlighted the importance of balanced NPK application in DOR production, suggesting that management strategy of these nutrients should be comprehensively considered with an aim to build an appropriate population structure with balanced plant density and individual growth.

Relative effectiveness of organic and inorganic nutrient sources in improving yield, seed quality and nutrient uptake of canola

The proper use of organic and inorganic nutrient sources is important to sustain high levels of crop production, while maintaining or enhancing soil and environmental quality. A 4-year (2009 to 2012) field experiment was established in spring 2009 on a Gray Luvisol (Typic Haplocryalf) loam soil at Star City, Saskatchewan, Canada, to determine the effectiveness of organic/biological (compost, wood ash [fine and granular], alfalfa pellets, distiller grain, thin stillage, glycerol, fish food additive, Penicillium bilaiae), inorganic/mineral (granular-gypsum, rapid release elemental S [RRES], rock phosphate [granular and fine]) and chemical/synthetic (granular-ammonium nitrate, triple super phosphate and potassium sulphate) nutrient sources (amendments/chemicals) in improving seed yield, straw yield, seed quality and nutrient uptake (N, P, K and S) in seed + straw of canola. Combined application of N, P and S chemical fertilizers (NPS) produced considerably greater seed yield, straw yield and nutrient uptake of canola compared to the unamended control in all four years. In treatments receiving only organic amendments, thin stillage produced the greatest seed yield, straw yield and nutrient uptake in all years, and it was similar to the NPS balanced fertilizer treatment, while fish food additive and distiller grain dry of wheat in 2009, 2011 and 2012, distiller grain dry of corn in 2009 and 2012, and compost and alfalfa pellets in 2011 and 2012 produced significantly greater seed yield, straw yield and nutrient uptake, when compared to the control. In treatments where chemical fertilizers were also applied, in addition to organic amendments, ap- plication of N fertilizer increased seed yield, straw yield and nutrient uptake substantially when combined with wood ash fine in 2009, 2010, 2011 and 2012, wood ash granular in 2009, 2011 and 2012, and glycerol in 2009 and 2012 (moderate increase in 2012). In the chemical fertilizer treatments, there was a reduction in seed yield, straw yield and nutrient uptake of canola when only N fertilizer was applied compared to the control (significant in 2010 and 2011). Application of P along with N (NP) increased seed yield, straw yield and nutrient uptake of canola compared to N alone treatment, but was less than the NPS treatment in all years. Application of S along with N (NS) increased seed yield, straw yield and nutrient uptake of canola further compared to the NP treatment, but it was still lower than the NPS treatment in 2010 and 2011. In treatments receiving inorganic/mineral amendments in addition to chemical fertilizers, application of N + P fertilizers substantially increased seed yield, straw yield and nutrient uptake in treatments receiving gypsum and RRES in 2009, 2010, 2011 and 2012. This suggests the potential of gypsum and RRES in preventing S deficiency in organic crops when grown on S-deficient soils, provided other nutrients are not limiting in the soil for crop growth. Seed yield, straw yield and nutrient uptake with application of N and S fertilizers in combination with rock phosphate and/or Penicillium bilaiae were similar to N + S treatment in most cases, except in 2011 when application of finely-ground or powder rock phosphate in a combination with N + S produced significantly greater yield and nutrient uptake than N + S with granular rock phosphate. This suggests little contribution of rock phosphate and/or Penicillium bilaiae in improving yield and nutrient uptake of canola, and improves the performance of fine rock phosphate only evident in the third growing season in 2011, after three consecutive applications, but not in 2012. In conclusion, some organic amendments showed potential for improvement in organic crop production, and in some other cases highest yield and nutrient uptake were

Identification of Quantitative Trait Loci Controlling Seed Physical and Nutrient Traits in Cotton

Cotton(Gossypium spp.) is the leading fiber crop,and an important source of the important edible oil and protein meals in the world.Complex genetics and strong environmental effects hinder

Effects of Planting Methods and Seed Density on Vegetable Yield and Nutrient Composition of <i>Solanum macrocarpon</i>and <i>Solanum scabrum</i>in Southwest Nigeria

Two field studies were carried out using Solanum macrocarpon and Solanum scabrum to investigate the effects of planting methods and seed density required for optimum biomass yield and nutrient content in southwest Nigeria. Two planting methods (drilling and broadcasting), and two seed densities (4 and 8 table spoon full) were investigated as a 2×2×3 factorial experiment in randomized complete block design and replicated three times. Four seed spoons gave 25.78 kg seeds ha-1 for S. macrocarpon and 20.67 kg·seeds·ha-1 for S. scabrum. Significant highest S. macrocarpon shoots (2.75 kg·m-2) and Ca, K, Fe and Zn contents and S. scabrum (2.95 kg·m-2) and Zn content, were obtained with drilling and four spoons of seeds compared with broadcasting and 8 spoons of seeds. This treatment gave average values for N, P, K, Mg, Ca, Na, Fe, Zn, Mn, Cu, Ca/P and Na/K ratio were 2.79%, 0.03%, 3.37%, 1.64%, 0.02%, 300 mg·kg-1, 100 mg·kg-1, 300 mg·kg-1, 8 mg·kg-1, 1.22 and 0.008 for S. macrocarpon and 2.05%, 0.27%, 5.81%, 3.27%, 2.91%, 0.09%, 280 mg·kg-1, 52.99 mg·kg-1, 359.35 mg·kg-1 and 22.42 mg·kg-1, 11.63 and 0.016 for S. scabrum. It was concluded that planting in drilling made weeding, fertilizer application, irrigation and harvesting more effective rather than by broadcasting, and four spoons of seeds per 9 m-2 produced deep green and broader leaves and balanced nutrient contents than eight spoons of seeds.

Crop rotation-dependent yield responses to fertilization in winter oilseed rape(Brassica napus L.)

Differences in soil physical, chemical and biological properties between paddy–upland and continuous upland rotations will influence nutrient relations and crop growth. With the aim of estimating rapeseed yield performance in response to fertilization in rice–rapeseed(RR) and cotton–rapeseed(CR) rotations, on-farm experiments were conducted at 70 sites across Hubei province, central China. The economically optimal fertilizer rates of winter oilseed rape in different rotations were determined. Field experiments showed that previous crops significantly influenced seed yields. Without N fertilization,seed yields were significantly lower for the RR rotation than for the CR rotation. The average yield increase ratio and agronomic efficiency associated with nitrogen(N)fertilization in the RR rotation were 96.6% and 6.56 kg kg- 1, significantly higher than those in the CR rotation. No seed yield differences were detected between the two rotations under phosphorus(P) and potassium(K) fertilization. In contrast to the CR rotation, N fertilizer played a more vital role in maintaining high seed yields in the RR rotation owing to the lower indigenous soil N supply. Compared with local N fertilizer recommendation rates for the RR rotation, on average an additional 18 kg N ha- 1was recommended according to the economically optimal N fertilizer rate(EONFR). In contrast, the EONFR was 14 kg N ha- 1lower than the locally recommended N fertilizer rate for the CR rotation. There were no differences between the two rotations for the average economically optimal P and K fertilization rates. Consequently, the average EONFR of winter oilseed rape could be reduced if cotton rather than rice preceded the winter oilseed rape.

Seed yeast cultivation for salad oil manufacturing wastewater treatment

The mixture of five yeast strains obtained from soil could remove about 85% TOC of oil rich wastewater in batch test. While the highest MLSS was obtained at an N∶C of 1∶5, the oil removal decreased with the increase of N∶C during yeast sludge cultivation. Ammonium chloride was the best nitrogen source for yeast cultivation from the viewpoint of yeast growth and oil utilization. An ammonia concentration of over 1300 mg/L led to mass death of yeast at a pH of 5. The ammonia concentration should be controlled at a level of 1000 mg/L or lower.

Seeds as a Source of Carbon, Nitrogen, and Phosphorus for Seedling Establishment in Temperate Regions: A Synthesis

Seeds are a source of organic (carbon, C) and mineral (nitrogen, N and phosphorus, P) nutrients for the growing seedling. There is much information on seed mass and N and P contents, and the relationship between these and seedling mass. Within the world’s temperate regions, these collectively show that N and P concentrations remain constant or rise with increase in seed mass and that seeds are larger and more nutrient-enriched in poorer soils. Seed N and P were more important than seed C in accounting for seedling mass in 85% of studies we assessed. In nutrient- and water-limited environments that are not light-limited, large seeds routinely provision the seedling with N and P that enhance C-fixation and thus general growth in the first wet season. This system is so efficient that growth response to soil nutrients may be negligible in first-year seedlings arising from seeds > 15 mg mass, N content > 5 mg and P content > 1.6 mg. The elongating taproot system absorbs nutrients and maintains water uptake as soil water retreats, enhancing the chances of survival in the first dry season. We outline an interpretative scenario for the special role of large seeds (>15 mg) in nutrient- and water-limited environments that recognizes the critical role of N and P for photosynthesis in ensuring sufficient C-supply to the rapidly descending roots for effective drought-avoidance by the young plant.

Soybean seed protein, oil, fatty acids, and mineral composition as influenced by soybean-corn rotation

Effects of crop rotation on soybean (Glycine max (L) Merr.) seed composition have not been well investigated. Therefore, the objective of this study was to investigate the effects of soybean-corn (Zea mays L.) rotations on seed protein, oil, and fatty acids composition on soybean. Soybeans were grown at Stoneville, MS, from 2005 to 2008 in five different scheduled cropping sequences. In 2007, following three years of rotation with corn, seed oleic acid percentage was significantly higher in any crop rotation than continuous soybean. The increase of oleic fatty acid ranged from 61 to 68% in 2007, and from 27 to 51% in 2008, depending on the rotation. The increase of oleic acid was accompanied by significant increases in seed concentrations of phosphorus (P), iron (Fe), and boron (B). In 2007, the increase of P ranged from 60 to 75%, Fe from 70 to 72%, and B from 34 to 69%. In 2008, the increase of P ranged from 82 to 106%, Fe from 32 to 84%, and B from 62 to 77%. Continuous soybean had higher linoleic:oleic ratio and linoleic: palmitic + stearic + oleic ratio, indicating that relative quantity of linoleic acid decreased in rotated crops. The total production of protein, oil, stearic and oleic fatty acids was the lowest in continuous soybean. The total production of palmitic acid was inconsistent across years. The results show that soybean- corn rotation affects seed composition by consistently increasing seed oleic fatty acid, P, Fe, and B concentrations. Higher oleic acid, unsaturated fatty acid, is desirable for oil stability and long-shelf storage. The mechanisms of how these nutrients are involved are not yet understood.

In vitro propagation of the endangered medicinal orchid,Dendrobium lasianthera J.J.Sm through mature seed culture

Objective:To study asymbiotic seed germination and mass propagation of Dendrobium lasianthera which is one of the endangered medicinal orchids using seeds.Methods:The 14 weeks old hand pollinated seeds were sown on Vacin and Went(VW)solid medium supplemented with various concentrations of peptone(1,2,3 g/L) and without peptone which was used as control treatment.At the 4,8,and 12 weeks after the seeds were sown,seed germination and shoot formation were investigated.To evaluate the role of organic nutrient additives on subsequent shoot development and root formation,particular shoots with about 1 cm length contains 1–2 leaves obtained from the seeds germination was cultured on VW medium additives with different of organic nutrient:15% coconut water,2 g/L peptone,150 g/L banana homogenate,and without organic nutrient was used as control.After 16 weeks of culture,the plantlet height,number of leaves,number of roots,leaf length and root length were recorded.Results:The supplementation of 2 g/L peptone in VW medium was proven to be suitable concentration for seed germination(100%) and shoot formation with 84.0% the protocorm development to phase 5(shoot).VW medium containing 15% coconut water was effectively improved the shoot development,with well developed roots and leaves compared to the other treatment and 95% of acclimatized plantlets survived.Conclusions:This protocol is an efficient way for the in vitro mass propagation of this Dendrobium lasianthera.

Endomycorrhizal Fungi and <i>Opuntia ficus-indica</i>Seed Germination on a Lunar Regolith Simulant

Endomycorrhizal fungi play an important role in the survival of plants on poor soils. Planting seeds into lunar soil at a lunar colony will be a challenge for seeds of any plant. The seeds will need a special microbial “tool kit” that will help them germinate and the young seedlings establish themselves. In this study, seeds of the prickly pear cactus, Opuntia ficus-indica, were chosen to examine the presence of fungus spores in the soil, inside the seeds and after germination in the rhizosphere, roots and other tissues of the young seedlings. The nutrient poor lunar regolith simulant JSC-1A was used as autoclaved or untreated growth medium. The mycorrhizal fungus Trichoderma viride was predominantly identified on the roots of new seedlings. This fungus also demonstrated the strongest effect on the germination rate of the seeds in comparison with other fungi isolated from the rhizosphere of Opuntia plants. T. viride was not detected within seeds and also not within seedlings, besides the root tips, whereas an arbuscular mycorrhizal Glomus species was seed-borne and present throughout most of the seedling. A close association between T. viride and a Glomus species associated with O. ficus-indica is demonstrated through light microscopic and electron microscopic images of the outside and inside root tips of the seedlings.

Photoperiod and Nitrogen Supply Limit the Scope of Northward Migration and Seed Transfer of Black Spruce in a Future Climate Associated with Doubled Atmospheric CO2 Concentration

The predicated changes in precipitation and temperature associated with the continued elevation of atmospheric CO2 concentration will trigger the northward shift of the Climate Envelopes for 130 North America tree species by as much as 10 degrees. However, climate envelope models do not take into account changes in other factors that may also influence the survival and growth of plants at the predicted new locations, such as photoperiod and nutrient regimes. This study investigated how photoperiod and nitrogen supply would affect the ecophysiological traits of black spruce (Picea mariana (Mill) B. S. P.) that are critical for survival and growth at new locations predicted by climate envelope models. We exposed black spruce seedlings to the photoperiod regime at the seed origin (PS) and that 10° north of the seed origin (PNM) as predicted by climate envelope models under the current and doubled atmospheric CO2 concentration and different levels of N supply (30 vs. 300 μmol·mol-1 N). We found that the PNM and the 30 μmol·mol-1 N supply both had negative impact on the development of seedling cold hardiness in the fall, and led to earlier burst of the terminal bud and greater rate of mortality in the following growing season. While the PNM stimulated seedling growth in the first growing season, the effect was not sustained in the second growing season. Our results suggest that the photoperiod regimes and poor nutrient conditions at higher latitudes will likely constrain the scope of the northward migration or seed transfer of black spruce.

濒危植物峨眉含笑种子发育的形态解剖研究

【目的】探究峨眉含笑种子发育过程中的形态解剖特征变化,解析其种子繁殖的生物学机制和濒危原因,为濒危植物的生态保育提供理论依据。【方法】以不同发育阶段的峨眉含笑种子为实验材料,采用石蜡切片法在显微镜下观测形态学变化和解剖结构特征,并用植物生理学方法对营养物质含量进行测定。【结果】种子发育初期为黄绿色圆球形,成熟后圆形子弹头状。外种皮红色革质,由3~4层表皮细胞构成;中种皮为橘红色肉质,由薄壁组织构成,细胞内后含物丰富,油脂感显著;内种皮中的扁平细胞分化成厚壁细胞,逐渐坚硬木质化,颜色由白色变为黑色。胚乳由薄壁细胞组成,胞内染成红色的后含物越来越多,形态从透明液态逐渐发育为坚实凝固态。种胚经历了球形胚、心形胚、鱼雷形胚和子叶形胚4个阶段,种子掉落时子叶形胚已发育完全。可溶性糖含量随种子发育呈先上升后下降的变化;淀粉和可溶性蛋白含量初期缓慢上升,中后期逐渐稳定;粗脂肪含量前期快速上升、后期积累放缓。【结论】种子发育过程中出现外种皮色彩鲜艳、中种皮油脂含量高、内种皮通透性差、种子早期停止生长、中后期胚乳发育异常和含胚率低等问题,导致峨眉含笑种子质量低下,限制了种子自然萌发和天然更新进程,是种群衰退甚至濒危的重要原因之一。

毛竹种子发育过程中形态和生理特性变化

【目的】揭示毛竹Phyllostachys edulis种子发育过程中形态和生理特性的动态变化规律,为人工进行宏观调控、获得优质毛竹种子提供理论参考。【方法】以桂林海洋山一带的开花毛竹为材料,采集开花后不同时期的毛竹种子,对其发育过程中的形态和生理指标进行观察测定。【结果】1)花后10~30 d毛竹种子胚和胚乳细胞分裂分化活动剧烈,种子长、宽、厚等性状增长速度较快;花后40~60 d种子胚和胚乳细胞形态发育成熟,种子长、宽、厚等性状增长速度减缓。2)不同发育时期毛竹种子的可溶性糖、粗淀粉及可溶性蛋白含量存在显著性差异(P <0.05),可溶性糖与粗淀粉含量均呈单峰曲线变化,可溶性蛋白含量在4.89%~5.82%范围内波动变化。3)不同发育时期毛竹种子的活性氧含量和抗氧化酶活性具有显著性差异(P <0.05),H_(2)O_(2)含量与POD、CAT活性呈单峰曲线变化,而O_(2)^(-)含量与SOD活性变化趋势相似。4)不同发育时期毛竹种子的内源激素含量存在显著性差异(P <0.05),IAA、GA_(3)及ZR含量均呈先升后降再升的趋势,ABA含量则呈单峰曲线变化,(IAA+GA_(3)+ZR)/ABA的比值呈先降后升的趋势,在花后40 d达到最小值,为1.001。【结论】花后10~30 d抗氧化酶活性以及内源激素含量逐渐升高,有效促进毛竹种子细胞代谢与分裂分化;花后30~60 d毛竹种子的分化活动基本结束并进入营养积累阶段,该时期抗氧化酶活性和内源激素逐渐下降,营养物质含量进一步增加。

辣木茎叶、籽、果荚营养成分及提取物抗氧化活性研究

以辣木茎叶、辣木籽、辣木果荚为原料,分析三种原料营养成分含量。以乙醇为提取溶剂,超声辅助法提取得到三种辣木粗提物,测定此三种辣木粗提物的总酚、类黄酮、可溶性糖的含量,以DPPH自由基、ABTS+自由基、羟自由基清除率以及亚铁还原能力等指标评价三种辣木提取物的体外抗氧化能力。结果表明:(1)辣木茎叶和辣木果荚的类黄酮、总酚、还原糖、碳水化合物、酸性洗涤纤维、中性洗涤纤维的含量明显高于辣木籽,辣木籽拥有较高的粗蛋白、粗脂肪含量;(2)辣木茎叶和辣木果荚粗提物的类黄酮和总酚含量明显高于辣木籽,辣木茎叶提取物的可溶性糖含量显著高于辣木籽和辣木果荚;(3)辣木茎叶粗提物表现出了较强的抗氧化活性。

品种和播种量互作对机械旱直播水稻与杂草养分竞争的影响

[目的]明确机械旱直播水稻品种和播种量对抑制杂草生长的效果,为实现机直播稻优质高产绿色高效栽培提供理论依据。[方法]以三系杂交稻川康优6308(C_(1))和两系杂交稻晶两优534(C_(2))为试材,设15kg/hm^(2)(S_(1))、22.5 kg/hm^(2)(S_(2))、37.5 kg/hm^(2)(S_(3))三个播种量,研究其对稻田主要杂草与水稻关键生育时期干物质累积、养分累积及转运的影响,并探讨品种和播种量互作下水稻与杂草养分竞争的关系。[结果]1)直播后29 d时,稻田杂草密度较水稻显著增加39.29%~47.16%,且杂草与水稻群体干质量比及养分累积比均高于1∶1,据此进行了一次必要性除草。2)除草前,品种C_(1)较C_(2)杂草密度显著降低91.34%~96.54%,水稻干物质累积量增加19.21%~30.24%,氮、磷、钾累积提高7.17%~34.59%;同一品种提高播种量,杂草量显著降低,相对S_(1),S_(2)和S_(3)处理杂草量显著降低21.95%~109.69%,水稻干物质累积量增加39.78%~94.52%,氮、磷、钾累积量提高10.11%~50.79%。3)除草后,直播43 d,杂草数量显著降低,品种C_(1)较C_(2)干物质累积量增加54.12%~66.97%,氮、磷、钾养分提高15.56%~47.45%;同一品种下,S_(2)和S_(3)较S_(1)处理水稻密度显著提高14.94%~32.34%,干物质累积量增加24.45%~85.07%,氮、磷、钾养分提高21.62%~98.34%;但随播种量的增加,结实期氮、磷、钾养分转运量与转运率,以及稻谷产量均呈先增加后降低趋势,以S_(2)处理最高。[结论]综合抑制杂草生长和稻谷产量,机械旱直播水稻以选用川康优6308配套22.5 kg/hm^(2)播种量,并依据稻田杂草总密度高于水稻且杂草与水稻群体干质量比及养分比1∶1时为最佳除草时机,可发挥水稻品种与播种量互作的优势控制杂草生长,减少除草剂使用,提高产量。

红花籽油营养成分和功效研究进展

为了对红花籽油产品开发提供参考,通过对相关既往研究的归纳总结,综述了红花籽油的主要营养成分、健康功效研究情况,介绍了红花籽油在其他领域的应用,并对未来的研究方向进行展望。红花籽油的营养功效成分主要有亚油酸、维生素E、植物甾醇、黄酮类化合物(主要为金合欢素)。红花籽油具有抗氧化、改善心脑血管健康、保护神经系统、改善肥胖等多种健康功效。红花籽油除食用外,在畜牧业中也具有一定的应用前景。今后应加大对红花籽油健康功效和作用机制的研究,创新红花籽油加工工艺,提高功效成分的保留率,促进红花籽油在多领域的应用。

‘凤丹’牡丹栽培及产业发展综述

该研究总结了影响‘凤丹’生长发育、产量的各项因素并结合阐述现阶段‘凤丹’综合开发利用的现状,揭示了‘凤丹’产业精细化发展所面临的主要挑战,以期对‘凤丹’以及整个牡丹产业的可持续发展提供参考依据。

油茶籽油品质性状研究进展

油茶籽油的品质和质量是衡量油茶品质的关键标准之一。目前,油茶籽油品质高低的评价指标主要集中在理化性质、脂肪酸组成及功能性营养成分等方面。其中不饱和脂肪酸总量、角鲨烯、维生素E的含量以及酸值、过氧化值等是评价油茶籽油品质的重要依据之一。随着油茶籽油品质性状的比较研究逐渐增多,对于这些性状合成相关基因的集中研究显得不够深入,并且大多数基因之间的相互作用机制尚未清楚。为进一步了解品质性状对油茶良种选育的影响,为选育高品质油茶品种提供参考,本文综述了油茶籽油脂肪酸组成及生物活性成分等品质性状的研究,并探讨了影响品质性状的因素。同时,分析了脂肪酸和功能性营养成分合成代谢相关基因的深层次分子研究进展,对开发油茶重要品质性状关联的分子标记具有指导意义。

39份子莲资源的营养品质分析

为了筛选出营养品质高的子莲资源,以39份子莲资源作为研究对象,对其莲子的蛋白质含量、淀粉酶含量及矿物质含量等11个莲子营养品质指标进行测定,并结合主成分分析、隶属函数分析法综合评价莲子的营养品质。结果表明:不同子莲资源的莲子营养品质指标差异较大,变异系数为0.27~0.76,其中,α-淀粉酶、Zn含量、VC含量变异幅度较大,莲子重量、含水量、K含量变异幅度较小。营养性状指标之间存在不同程度的相关性,其中,VC含量与P和K含量呈现正相关,而与β-淀粉酶呈现负相关;所分析的几种矿物质含量均呈正相关。P、K、Fe和VC含量可以作为子莲莲子营养品质的评价性指标。综合整体营养品质考虑,筛选出优良子莲资源7份:‘建选17号’‘太空莲2号’‘九华皓月’‘太空莲36号’‘采桑湖莲’‘宣莲6号’和‘白湘莲’。此外,‘日华寸三莲’的VC及矿质元素含量最高;‘台湾子莲’的β-淀粉酶含量最高;‘赣莲-62号’的含水量最高,也具有各种不同方面的开发潜力。综合评价表明,‘建选17号’‘太空莲2号’‘九华皓月’‘太空莲36号’‘采桑湖莲’‘宣莲6号’和‘白湘莲’7个子莲资源的莲子整体营养品质高,可以结合产量优先考虑推广,并为育种亲本的选择提供参考。

施氮量和收获时间对羊草种子产量的影响

羊草(Leymus chinensis)种植过程中常见发芽率低、分蘖低,甚至颗粒无收的现象,增施氮肥能在一定程度上改善这种情况,收获时间是影响种子产量的关键因素。为此,研究施氮量[不施氮、150、300 kg·(hm^(2)·a)^(-1)]和收获时间(盛花期后25、30、35、40、45 d)对羊草种子产量的影响,以明确新疆地区羊草的施氮量和最佳收获时间。结果表明:1)施氮量和收获时间对羊草种子发芽率、产量及其构成因素产生显著影响。盛花期后35 d收获与40、45 d收获相比,羊草种子发芽率、产量及产量构成因素没有显著差异。盛花期后25 d收获,150 kg·(hm^(2)·a)^(-1)处理的种子发芽率比不施氮和300 kg·(hm^(2)·a)^(-1)处理分别增加了31.25%和12.51%。2)施氮量显著提高了羊草各部位的全氮含量,收获时间对羊草各部位全氮含量并没有显著影响,羊草各部位全磷含量随着施氮量的增加呈现先增加后降低的趋势。研究结果显示,在新疆羊草种子生产时,适宜的施氮量是150 kg·(hm^(2)·a)^(-1),最佳收获时间为盛花期后35 d。