不同磷效率大豆基因型根形态构型对低磷胁迫的响应

探讨大豆根系形态构型指标在低磷胁迫下的适应性反应,研究根系形态构型指标与磷效率的关系。本试验选用3个“磷低效”大豆基因型D3、D17和D18及“磷高效”大豆基因型D34、D37和D38,采用田间试验,设高、低磷两个处理,对大豆基因型磷效率与根形态构型指标的关系进行了研究。结果表明,在高磷处理下,供试大豆根系各形态构型指标和根干生物量均无显著差异,在低磷处理下,各基因型间差异达到显著水平。相关分析表明,根长、根表面积和根生物量与地上部干生物量达到显著或极显著正相关,根直径与磷效率相关系数未达到显著水平。低磷胁迫时,根长、根表面积与根生物量影响植物的磷效率,而根直径对磷效率的影响较小。因此可以把根长、根表面积作为大豆磷效率筛选的重要指标,把根生物量作为辅助筛选指标。     

不同供磷水平小麦苗期根系特征与其相对产量的关系

研究了缺磷条件下不同基因型小麦苗期根系形态学及生理学适应特征 ,结果表明 :在缺磷环境中 ,小麦根轴数量和侧根长度明显减小 ,同化物向根部的分配比例增加 ,根轴长度、侧根数量和根系长度等均是显著提高。供试基因型小麦的根轴数量及其长度的差异在每个供磷水平及不同供磷水平之间均是显著的 ,说明这两种性状的差异是由基因型和环境因素共同决定的 ;而侧根特征的差异只在不同供磷水平之间是显著的 ,表明侧根性状主要是受环境因素控制的。对 6种基因型小麦的研究表明 ,高磷水平的小麦种子根的生长角度明显低于低磷处理的小麦 ,根角之间存在着显著的基因型差异。在缺磷条件下 ,6种基因型小麦完整根系分泌的酸性磷酸酶活性、根轴数量、根轴长度、根生长角度和根系长度之间均存在着显著的基因型差异。相关分析表明 ,缺磷条件下的小麦苗期根系形态指标和根系分泌的酸性磷酸酶活性的交互作用与小麦的相对产量之间具有显著的线性关系 ,这种关系说明以上 5种性状均可作为早期有效地筛选磷高效小麦品种的指标     

不同磷水平下大豆根系性状的遗传特性分析

在田间两种磷水平下,应用大豆RIL群体对根总长、根总表面积、根宽、根冠比、根干重和根磷含量等6个根系性状参数和6个涉及植株磷含量、生物量及产量性状的指标进行遗传特性研究,结果发现在不同磷水平下,大豆重组自交系群体根系性状的变异幅度较大,符合正态分布的特征.土壤磷水平不仅促进了大豆根系形态的变化,同时也影响到根系构型的改变.低磷胁迫条件下,根系性状与植株磷含量、生物量及产量之间呈极显著相关关系,并且这些根系性状都具有较高的广义遗传率(0.47～0.60),可以作为选择指数应用于作物磷营养效率的遗传改良中.在根系性状的6个指标中,以根总长、根总表面积、根干重、根磷含量等4个参数与植株吸磷量、生物量及产量的关系最为密切,可以作为评价不同磷水平下植物基因型差异的可靠指标,而根宽和根冠比则可作为特定的磷胁迫条件下基因型差异的筛选指标.     

磷胁迫下不同基因型大豆苗期根系形态及生物量差异的研究

在磷胁迫[0mmol/L(P),砂培]条件下,对不同基因型大豆苗期在根系形态、生物量等方面的差异进行了研究,结果表明：磷高效基因型在两叶期并未发挥出其基因型潜力的优势;四叶期,磷高效基因型的侧根数、侧根长、根系吸收面积、茎叶干重等性状的受抑制程度均显著低于磷中、低效基因型,而地下干重、根冠比却受到了较中、低效基因型更强的诱导作用。综合评价表明,磷高效基因型的综合值（评价磷效率特性的综合指标）显著高于磷中、低效基因型,显示出了较强的抗磷胁迫能力,但磷高效基因型并非所有性状都表现突出;四叶期可作为大豆耐低磷胁迫的筛选期,根表面积和活跃吸收面积可作为衡量磷效率特性的特异性指标。     

磷胁迫下不同基因型大豆苗期根系形态及生物量的差异

在磷胁迫[0mmol/L(P),砂培]条件下,对不同基因型大豆苗期在根系形态、生物量等方面的差异进行了研究,结果表明:磷高效基因型在两叶期并未发挥出其基因型潜力的优势;四叶期,磷高效基因型的侧根数、侧根长、根系吸收面积、茎叶干重等性状的受抑制程度均显著低于磷中、低效基因型,而地下干重、根冠比却受到了较中、低效基因型更强的诱导作用。综合评价表明,磷高效基因型的综合值(评价磷效率特性的综合指标)显著高于磷中、低效基因型,显示出了较强的抗磷胁迫能力,但磷高效基因型并非所有性状都表现突出;四叶期可作为大豆耐低磷胁迫的筛选期,根表面积和活跃吸收面积可作为衡量磷效率特性的特异性指标。     

甘蓝型油菜重组自交系苗期磷效率的评价

设置低磷P1 (5 μmol L^-1)和高磷P2 (1 000 μmol L^-1)处理水培甘蓝型油菜重组自交系群体的135个株系及亲本的幼苗, 以地上部干重(SDW)、根干重(RDW)、根冠比(R/S)、主根长(AMRL)、地上部磷积累量(SPU)、总磷吸收量(TPU)、磷利用效率(PUE)作为耐性指标, 调查群体各株系和亲本间对缺磷反应的差异, 并对各性状参数与磷吸收、利用效率进行相关性分析。结果表明: (1) 低磷胁迫严重抑制甘蓝型油菜苗期生长, 所调查的各性状均表现出显著差异,其中地上部干重和根干重的变异系数较大;(2) 2种处理条件下, 各株系的地上部干重、根干重、根冠比和主根长4个性状均表现出显著分离, 并呈现正态分布,低磷处理的分离更为明显;(3) 相关性分析表明, 相对地上部干重和根干重可以作为磷效率的主要评价指标,为了避免遗传因素影响, 还应考虑低磷处理下基因型各性状的绝对差异;(4) 通过上述筛选指标,确定065﹑102﹑070为候选的极端磷高效基因型, 105﹑076﹑011等为候选的极端磷低效基因型。     

茄子氮高效基因型苗期筛选指标的研究

为明确茄子氮高效基因型苗期筛选指标,以茄子高氮高效低氮高效型基因型06-991和高氮高效低氮低效型基因型06-867为材料,采用溶液培养方法在高氮(11 mmo L/L)和低氮(2 mmo L/L)处理下,研究茄子苗期植株形态、根系特征和氮素在各个器官中的累积与分配的特性。结果表明,高氮处理下06-991和06-867茄子的植株形态、根系形态差异不显著;低氮处理下06-991的株高、叶片总叶绿素含量、植株干质量、平均根长、根体积、根干质量和植株氮累积量显著高于06-867,分别达到06-867的1.40,1.78,1.29,1.30,1.67,2.00倍。06-991的根冠比和植株向根部分配的氮素显著高于06-867。茄子各性状与氮素累积量相关性分析表明,2个氮水平下植株干质量和根干质量与植株氮素累积量呈极显著正相关,适合作为茄子苗期氮高效基因型筛选指标。     

低磷胁迫对不同基因型小麦品种苗期性状的影响

为研究低磷胁迫对小麦苗期性状的影响,在对照(200 μmol/L KH2PO4)和低磷(5 μmol/L KH2PO4)条件下比较了6个不同基因型小麦品种苗期性状指标。结果表明,小麦根系和地上部对低磷胁迫的反应不同,低磷诱导小麦根系伸长,根系生物量（根鲜重和根干重）增加,供试的6个小麦品种在低磷条件下的根系鲜重和干重与对照相比差异均达到显著或极显著水平。低磷处理对地上部则表现出抑制作用,但对不同品种的影响程度差异较大。总体来看,低磷胁迫处理对小麦根系性状的影响大于地上部性状,不同苗期性状受低磷胁迫影响的程度分别为：根系鲜重>最长根长>根系干重>地上部鲜重>地上部干重>苗长。6个供试小麦品种中,‘中国春’对低磷胁迫最为敏感,而‘京411’的耐低磷性相对较强。     

不同施磷条件下大豆植株农艺性状与磷效率的关系

【研究目的】为了寻找直观、简便、可靠的用于磷效率筛选的农艺性状指标,探讨大豆植株农艺性状与磷效率的关系,【方法】试验选用3个“磷低效”大豆基因型HND3、HND17和HND18及“磷高效”大豆基因型HND34、HND37和HND38,采用高、低磷土壤盆栽试验,对大豆基因型磷效率与植株农艺性状的关系进行了研究。【结果】结果表明,在相关分析中,低磷（-P）和高磷（＋P）处理的x1（株高）、x4（单株荚数）、x5（单株粒数）、x8（地上部干重）和x9（根干重）,（-P）处理x3（节数）和（＋P）处理x2（分枝数）与磷效率（籽粒产量）均达到了显著或极显著水平。经逐步回归分析,建立了回归方程：（-P）处理：y=391.629＋9.271x1-2.674x2＋7.236x4＋76.932x9;（＋P）处理：y=699.882＋3.572x1＋22.956x4-191.103x6。在通径分析中,各农艺性状对籽粒产量的重要性依次为：（-P）处理：株高（0.456）〉单株荚数（0.360）〉根干重（0.267）〉分枝数（-0.021）;（＋P）处理：单株荚数（0.845）〉株高（0.126）〉每荚粒数（-0.117）。【结论】研究表明,在磷高效大豆基因型筛选中,应该考虑高、低磷条件下株高、单株荚数和根干重的综合表现。     

燕麦根系对缺磷胁迫的适应性反应

采用溶液培养的方法,在燕麦苗期,研究了磷素充足供应和缺磷胁迫两种条件下根系形态指标的变化。结果表明,经过30d的缺磷胁迫,燕麦根系生物量显著低于充足供磷处理,但根系总长并未表现为缺磷处理显著低于充足供磷处理,而且根冠比、比根长却表现为缺磷处理显著高于磷素充足供应处理。缺磷条件下比根长的增加与根轴直径的减小是一致的,因此根轴横向生长减弱可能是导致缺磷燕麦根系比根长增加的原因。由于比根长的增加意味着消耗同样的同化产物,却可以形成具有较大吸收范围的根系,因此燕麦根轴直径减小、比根长的增加是燕麦对缺磷胁迫的适应。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.