氮磷钾胁迫下不同D基因组人工合成小麦生长和养分积累差异

【目的】人工合成小麦具有很多优良性状,是现代小麦遗传改良的重要基因资源。本研究以具有相同AB基因组、不同D基因组的人工合成小麦材料Syn79(S79)和Syn80(S80)为供试材料,研究在氮磷钾胁迫下其生长、养分积累、养分分配和利用,差异,为小麦抗逆性基因定位和抗逆性遗传改良提供依据。【方法】采用盆栽试验,以施用N 0.20、P2O50.15和K2O 0.15 g/kg土为正常氮磷钾水平,以不施氮磷钾作为胁迫,设立4个处理:NPK(CK)、N0PK、NP0K、NPK0。小麦整个生育期每隔1个月调查1次株高和分蘖,成熟期,将小麦分根、茎叶、颖壳(穗)和子粒4个部分整理样品,收集株高、有效分蘖数、根长、穗长、根重、茎叶重、穗重、籽粒重、小穗数、穗粒数、穗粒重、千粒重和结实率。【结果】D基因组来源不同的人工合成小麦S79和S80在氮磷钾胁迫下生长、养分积累、分配和利用方面差异很大。从生长角度看,S80对氮磷胁迫敏感性低于S79,其在氮磷胁迫下长势优于S79,主要表现为株高、有效分蘖、分蘖成穗率、单株茎叶、颖壳和籽粒重等农艺性状显著好于S79。S80在氮磷钾胁迫下株高、根长和根冠比显著增加,S79的显著降低。S79在钾胁迫下农艺性状表现好于S80,主要表现为低钾环境下S79单株根重、茎叶重、颖壳重和籽粒重均高于S80。从养分积累、分配和利用看,S79在氮钾胁迫下单株氮磷钾养分积累高于S80,但S80在氮钾胁迫下的氮磷钾利用效率和收获指数均高于S79;磷胁迫下,S80单株、单株茎叶和单株颖壳中氮磷钾养分积累高于S79,但其利用效率和收获指数低于S79。S80在氮磷胁迫下籽粒中养分分配率较高,S79在钾胁迫下籽粒中养分分配较好。【结论】S79和S80在不同养分胁迫下生长、养分积累、分配和利用产生差异。S80耐低氮低磷,S79耐低钾;S80在氮钾胁迫下对氮磷钾养分利用较高,S79在磷胁迫下对氮磷钾养分利用较高。S80在养分胁迫下通过增加根长扩大养分供给范围,增加养分供给量,满足作物生长,加快养分向穗部转运,降低对籽粒产量影响。

Difference in growth and nutrient accumulation of synthetic wheat with different D genome under nitrogen,phosphorus and potassium stresses

【Objectives】 Synthetic wheat has many desirable qualities derived from D genome of Aegilops tauschii. The synthetic wheat cultivar, S79 and S80, have the same A and B genomes but different D genome. The two cultivars were used to evaluate the growth, nutrient use efficiency and tolerance to nitrogen(N), phosphorus(P) and potassium(K) stresses,which will provide information for the localization of tolerance genes and improvement of heredity in wheat breeding in the future. 【Methods】 A pot experiment was carried out with the two synthetic wheat cultivar, S79 and S80. N 0.20 g/kg、P2O5 0.15 g/kg and K2O 0.15 g/kg were set as sufficient supplies, no N, P and K as stress. Four treatments were designed: NPK(CK), N0PK, NP0K and NPK0. The plant height and tillering number were investigated once a month during the whole growing stage. The whole plant samples were collected at harvest and divided into root, stem and leaves, shells(ears) and grains. The yield components were investigated. 【Results】 The significant differences in growth, nutrient accumulation and nutrient use efficiency were found between S79 and S80 under N, P or K stress. S80 exhibited lower sensitivity to N and P stress than S79, and demonstrated better performance on growing vigor, effective tiller, stem, leaf, glumes and grain yield per plant. Plant height, root length and the ratio root versus shoot from S80 increased significantly, but these indexes in S79 reduced significantly. Wherea, S79 had lower sensitivity to low K, and showed better agronomic performance than S80 under K stress. Root weight, stem and leaf weight, spike weight and grain weight per plant of S79 were higher than those of S80 under K stress. Although S79 accumulated more N, P and K than S80 under N and K stress, but N, P and K use efficiency and harvest index of S80 were higher than those of S79. Accumulation of N, P and K in the stem, leaf and spike of S80 was higher than those in S79 under P stress. While, N, P and K use efficiency and harvest index of S80 were lower than those of S79. Nutrient distribution rate in grain of S80 was higher than that in S79 under N and P stress, while S79 had higher nutrient distribution rate than S80 under K stress.【Conclusions】The synthetic wheat S80 had the stronger tolerance to N, P stress, and S79 had the greater toleration to K stress. N, P and K use efficiency of S80 were higher than that of S79 under N and K stress, but these indexes of S79 were higher than those of S80 under P stress. S80 increased root length, and expanded the scope of nutrient supply, and increased nutrient supply, and met the requirement for crop growth, and accelerated nutrient transport to ears, and then reduced effect of N, P and K stress on grain yield.