| The experiment was carried out at Zhangjiakou during growing season in2011and2012by the cultivar “Baxuan3” in rain-fed conditions, respectively, and at Yuzhongduring growing season in2012and2013by the cultivar “Longyaza1” in irrigated landconditions, respectively. To study nitrogen (N) and phosphorus (P) accumulation,distribution, and remobilization characters, N and P use efficiency of each organ andaboveground plant parts in oilseed flax in rain-fed and irrigated land conditions,respectively; and change characters of N metabolism major products and enzyme ofoilseed flax in irrigated land conditions. The major conclusions of experiment are asfollow:1. Nitrogen accumulation increased with increasing N application in stem, leaf,non-grains (including stalk, flower bud, sepal, carpopodium, and pericarp), andaboveground plants of oilseed flax. Nitrogen accumulation continuously increased in stemof the whole growth and development stages but reached peak in leaf at anthesis stage,then decreased. Proportion rate of seed N accounted up51.46%in aboveground plant parts,followed by stem N accounted up36.76%, and leaf N and non-grains N less inaboveground plants of N. Seed N56.52%～79.83%came from leaf N translocation ofoilseed flax and4.93%～11.86%came from non-grains N translocation in rain-fedconditions. Seed N63.50%～77.65%came from leaf N translocation of oilseed flax and9.51%～16.48%came from non-grains N translocation in irrigated conditions. Nitrogenaccumulation each growth stage in oilseed flax of aboveground plant parts, Naccumulation was less at seedling stage, accounted up14.02%～18.49%of the wholegrowth stage in rain-fed conditions and9.12%～19.27%in irrigated conditions,respectively. The maximum of N accumulation was at anthesis stage, accounted up34.42%～44.24%of the whole growth stage N accumulation in rain-fed conditions and29.92%～45.06%in irrigated conditions, respectively.2. Phosphorus accumulation increased with increasing P application in abovegroundplants of oilseed flax. Phosphorus accumulation continuously increased in stem of the whole growth and development stages but reached peak in leaf at anthesis stage, thendecreased. Proportion rate of aboveground plant parts P accumulation in oilseed flaxaccounted up79.02%～88.17%from anthesis stage to maturity in rain-fed conditions and67.30%～77.84%in irrigated conditions, respectively. Proportion rate of seed Paccumulation accounted up46.07%and was the most, followed by stem P accounted up42.01%in aboveground plant parts of oilseed flax at maturity stage. Phosphorustranslocation of leaf were34.04%～62.17%in rain-fed conditions and50.89%～71.85%in irrigated conditions, respectively. Seed P20.46%～35.93%came from leaf Ptranslocation of oilseed flax in rain-fed conditions and23.62%～48.03%came from leaf Ptranslocation of oilseed flax in irrigated conditions, respectively.3. Seed yield of oilseed flax increased with increasing N and P application. Seed yieldof oilseed flax increased by30.84%in rain-fed conditions and42.60%in irrigatedconditions, respectively, when N application rate ranged from90to150kg/hm2. Seed yieldof oilseed flax increased by31.46%in rain-fed conditions and22.57%in irrigatedconditions, respectively, when P2O5application rate ranged from105to150kg/hm2.Apparent N recovery efficiency of oilseed flax reached the maximum was20.53%inrain-fed conditions and25.12%in irrigated conditions, respectively. Agronomic useefficiency of N of oilseed flax reached the maximum was6.33kg kg-1under rain-fedconditions and7.69kg kg-1under irrigated conditions, respectively. Agronomic useefficiency of P in oilseed flax reached7.43kg kg-1under rain-fed and9.15kg kg-1underirrigated conditions, respectively.4. Chlorophyll, free amino acid, and soluble protein synthesis promoted in stem andleaf of oilseed flax as increasing N and P application. In the present study designed level ofN and P application, compared with no fertilizer, chlorophyll content increased by rangedfrom6.19%to19.38%，free amino acid content increased by ranged from5.92%to35.20%,and soluble protein content increased by ranged from12.26%to51.32%in leaf,respectively. Chlorophyll content increased by ranged from4.97%to24.46%，free aminoacid content increased by ranged from12.59%to57.16%, and soluble protein contentincreased by ranged from7.63%to45.03%in stem, respectively. Compared to applicationP fertilizer, applied N chlorophyll content increased by an average of8.86percent point, free amino acid content increased by an average of21.55percent point, and soluble proteincontent increased by an average of26.39percent point in leaf, respectively; chlorophyllcontent increased by an average of13.95percent point, free amino acid content increasedby an average of31.48percent point, and soluble protein content increased by an averageof25.71percent point in stem, respectively.5. Improved nitrate reductase (NR) and glutamine synthetase (GS) activity asapplication N and P. In the present study designed level of N and P application, comparedwith no fertilizer, NR activity increased by5.71%~30.40%in leaf and7.04%~41.99%instem of oilseed flax, respectively. Compared to application P, application N fertilizerincreased NR activity by an average of18.23percent point in leaf and24.22percent pointin stem of oilseed flax, respectively. GS activity increased by an average of9.57%~55.84%in leaf and10.88%~46.01%in stem of oilseed flax, respectively, compared with noapplication fertilizer, when application N and P. Compared to application P, application Nfertilizer increased GS activity by an average of33.37percent point in leaf and24.32percent point in stem of oilseed flax, respectively. The indicated that effected on NR andGS activity of N was first, and secondly P. |
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