Can soil nitrate: ammonium ratios influence plant carbon: nitrogen ratios of the early succession plant? Can plant carbon: nitrogen ratios limit the plant growth in early succession? To address these two question...Can soil nitrate: ammonium ratios influence plant carbon: nitrogen ratios of the early succession plant? Can plant carbon: nitrogen ratios limit the plant growth in early succession? To address these two questions, we performed a two-factor (soil nitrate: ammonium ratio and plant density) randomized block design and a uniform-precision rotatable central composite design pot experiments to examine the relationships between soil nitrate: ammonium ratios, the carbon: nitrogen ratios and growth rate of Artemisia sphaerocephala seedlings. Under adequate nutrient status, both soil nitrate: ammonium ratios and plant density influenced the carbon: nitrogen ratios and growth rate of A. sphaerocephala seedlings. Under the lower soil nitrate: ammonium ratios, with the increase of soil nitrate: ammonium ratios, the growth rates of plant height and shoot biomass of A. sphaerocephala seedlings decreased significantly; with the increase of plant carbon: nitrogen ratios, the growth rates of shoot biomass of A. sphaerocephala seedlings decreased significantly. Soil nitrate: ammonium ratios affected the carbon: nitrogen ratios of A. sphaerocephala seedlings by plant nitrogen but not by plant carbon. Thus, soil nitrate: ammonium ratios influenced the carbon: nitrogen ratios of A. sphaerocephala seedlings, and hence influenced its growth rates. Our results suggest that under adequate nutrient environment, soil nitrate: ammonium ratios can be a limiting factor for the growth of the early succession plant.展开更多
Rice with polyembryony characterized bytwin seedlings is a good genetic tool for apomixisresearch.A study on the effect of five plantgrowth regulators(IAA,KT,GA,2,4-D and6-BAP)on rate of twin seedlings in 3 rice varie...Rice with polyembryony characterized bytwin seedlings is a good genetic tool for apomixisresearch.A study on the effect of five plantgrowth regulators(IAA,KT,GA,2,4-D and6-BAP)on rate of twin seedlings in 3 rice varie.ties with polyembryony(Shuang 3,Shuang 13and Lu 52)was conducted.The results showed展开更多
<div style="text-align:justify;"> <i><span style="font-family:Verdana;">Sipha</span></i><span style="font-family:Verdana;"> <i>maydis</i>&l...<div style="text-align:justify;"> <i><span style="font-family:Verdana;">Sipha</span></i><span style="font-family:Verdana;"> <i>maydis</i></span><span style="font-family:""><span style="font-family:Verdana;"> Passerini (Hemiptera: Aphididae) is a pest of cereals in many regions of the world and was identified as an invasive pest of the US in 2007. Regional surveys from 2015-2017 revealed this pest was broadly distributed throughout many of the western Great Plains states where it is a potential threat to cereal production. The common name hedgehog grain aphid, HGA, has been associated with </span><i><span style="font-family:Verdana;">Sipha</span></i> <i><span style="font-family:Verdana;">maydis</span></i><span style="font-family:Verdana;"> in the US. Cross-resistance where a plant is resistant to one aphid species and is also resistant to another species</span></span><span style="font-family:Verdana;"> that</span><span style="font-family:""><span style="font-family:Verdana;"> is known to occur. Six barleys were evaluated for cross-resistance to HGA: Russian wheat aphid, RWA, resistant germplasms STARS 9301B and STARS 9577B and cultivar “Mesa”;greenbug, GB, resistant germplasm STARS 1501B and cultivar “Post 90”;and RWA and GB resistant experimental line 00BX 11-115. Cultivars “Morex” and “Schuyler” were susceptible controls. Antixenosis was measured 5 days after infestation by HGA. Seedling damage ratings and reductions in seedling growth were recorded after 17 days of infestation. Intrinsic rate of increase, </span><i><span style="font-family:Verdana;">r</span><sub><span style="font-family:Verdana;">m</span></sub></i><span style="font-family:Verdana;">, of HGA was determined by following the development of newborn aphids to adulthood and reproduction. 00BX 11-115 and Post 90 had significantly greater antixenosis (fewer aphids/seedling), significantly lower plant damage ratings, and significantly lower intrinsic rates of increase than other entries. Differences in seedling growth were not significant. 00BX 11-115 and Post 90 were the only entries with the </span><i><span style="font-family:Verdana;">Rsg</span></i><span style="font-family:Verdana;">1 greenbug resistance gene. </span><i><span style="font-family:Verdana;">Rsg</span></i><span style="font-family:Verdana;">1 greenbug resistance confers cross-resistance to HGA in the seedling stage.</span></span><span style="font-family:Verdana;"></span> </div>展开更多
基金supported in part by the National Basic Re-search Program of China (2009CB421303)supported by National Natural Science Foundation of China (30970546)
基金supported in part by the National Basic Research Program of China (2009CB421303)supported by National Natural Science Foundation of China (30970546)
文摘Can soil nitrate: ammonium ratios influence plant carbon: nitrogen ratios of the early succession plant? Can plant carbon: nitrogen ratios limit the plant growth in early succession? To address these two questions, we performed a two-factor (soil nitrate: ammonium ratio and plant density) randomized block design and a uniform-precision rotatable central composite design pot experiments to examine the relationships between soil nitrate: ammonium ratios, the carbon: nitrogen ratios and growth rate of Artemisia sphaerocephala seedlings. Under adequate nutrient status, both soil nitrate: ammonium ratios and plant density influenced the carbon: nitrogen ratios and growth rate of A. sphaerocephala seedlings. Under the lower soil nitrate: ammonium ratios, with the increase of soil nitrate: ammonium ratios, the growth rates of plant height and shoot biomass of A. sphaerocephala seedlings decreased significantly; with the increase of plant carbon: nitrogen ratios, the growth rates of shoot biomass of A. sphaerocephala seedlings decreased significantly. Soil nitrate: ammonium ratios affected the carbon: nitrogen ratios of A. sphaerocephala seedlings by plant nitrogen but not by plant carbon. Thus, soil nitrate: ammonium ratios influenced the carbon: nitrogen ratios of A. sphaerocephala seedlings, and hence influenced its growth rates. Our results suggest that under adequate nutrient environment, soil nitrate: ammonium ratios can be a limiting factor for the growth of the early succession plant.
文摘Rice with polyembryony characterized bytwin seedlings is a good genetic tool for apomixisresearch.A study on the effect of five plantgrowth regulators(IAA,KT,GA,2,4-D and6-BAP)on rate of twin seedlings in 3 rice varie.ties with polyembryony(Shuang 3,Shuang 13and Lu 52)was conducted.The results showed
文摘<div style="text-align:justify;"> <i><span style="font-family:Verdana;">Sipha</span></i><span style="font-family:Verdana;"> <i>maydis</i></span><span style="font-family:""><span style="font-family:Verdana;"> Passerini (Hemiptera: Aphididae) is a pest of cereals in many regions of the world and was identified as an invasive pest of the US in 2007. Regional surveys from 2015-2017 revealed this pest was broadly distributed throughout many of the western Great Plains states where it is a potential threat to cereal production. The common name hedgehog grain aphid, HGA, has been associated with </span><i><span style="font-family:Verdana;">Sipha</span></i> <i><span style="font-family:Verdana;">maydis</span></i><span style="font-family:Verdana;"> in the US. Cross-resistance where a plant is resistant to one aphid species and is also resistant to another species</span></span><span style="font-family:Verdana;"> that</span><span style="font-family:""><span style="font-family:Verdana;"> is known to occur. Six barleys were evaluated for cross-resistance to HGA: Russian wheat aphid, RWA, resistant germplasms STARS 9301B and STARS 9577B and cultivar “Mesa”;greenbug, GB, resistant germplasm STARS 1501B and cultivar “Post 90”;and RWA and GB resistant experimental line 00BX 11-115. Cultivars “Morex” and “Schuyler” were susceptible controls. Antixenosis was measured 5 days after infestation by HGA. Seedling damage ratings and reductions in seedling growth were recorded after 17 days of infestation. Intrinsic rate of increase, </span><i><span style="font-family:Verdana;">r</span><sub><span style="font-family:Verdana;">m</span></sub></i><span style="font-family:Verdana;">, of HGA was determined by following the development of newborn aphids to adulthood and reproduction. 00BX 11-115 and Post 90 had significantly greater antixenosis (fewer aphids/seedling), significantly lower plant damage ratings, and significantly lower intrinsic rates of increase than other entries. Differences in seedling growth were not significant. 00BX 11-115 and Post 90 were the only entries with the </span><i><span style="font-family:Verdana;">Rsg</span></i><span style="font-family:Verdana;">1 greenbug resistance gene. </span><i><span style="font-family:Verdana;">Rsg</span></i><span style="font-family:Verdana;">1 greenbug resistance confers cross-resistance to HGA in the seedling stage.</span></span><span style="font-family:Verdana;"></span> </div>