Identification of a Long Rice Spikelet Mutant

A spontaneously occurring rice (Oryza sativa L.) mutant, characterized by homeotic conversion in glumes and stamens, was found in the progeny of a cross. The mutant showed long glumes and glumaceous lodicules and morphological transformation of stamens into pistils. Mutant florets consisted of 1 to 3 completely developed pistils, some pistilloid stamens with filaments, but tipped by bulged tissue and 0 to 3 stigmas. It seems that the mutant phenotype of the homeotic conversions in glumes and stamens is similar to that of the B loss-of-function mutants in Arabidopsis and Antirrhinum. The mutant is controlled by a single recessive gene as a segregation ratio of 3:1 (wild type to mutant plants) was observed in the F2 generation.     

Inheritance of Ear Tip-Barrenness Trait in Maize

The aim of this paper is to study the inheritance pattern of ear tip-barrenness trait in maize （Zea mays L.）. Ear tipbarrenness trait in maize can be classified into two types, tip-barren and tip-barrenless. Two inbred lines, lx01-3 （tipbarrenless type）, wx04-1 （tip-barren type）, and their F1, F2, BC1, BC2 generations were analyzed on their ear tip-barrenness types. Results showed that F1 was tip-barren type; the ratio of tip-barren type versus tip-barrenless type followed a 12.78： 1 ratio in F2 segregation population and a 2.75：1 ratio in BC1. Z2 test indicated that the trait of ear tip-barrenness type followed an inheritance pattern of 2 duplicate dominant genes. SPSS analysis indicated that the trait of ear tip-barrenness length is of abnormal distribution. Above results mean that： （1） The trait of maize ear tip-barrenness type is controlled by 2 duplicate dominant genes; tip-barren type is dominant over tip-barrenless type; （2） the trait of tip-barrenness length is a quantitative character controlled by polygene with major genes expected.     

低叶绿素b水稻突变体的抗氧化酶系统研究(英文)

[Objective] The mitigative effect of antioxidase system of a rice mutant with low chlorophyll b on photooxidative damage was studied.[Method] A rice mutant with low chlorophyll b and its wild type were taken as experimental materials to comparatively research their peroxide (H2O2) contents, the activity and isozymes of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in chloroplast.[Result] Compared with the wild type, there were many kinds of SOD, POD and CAT isozymes in leaf cells and chloroplast cell of mutant, and the activity of SOD, POD and CAT isozymes in leaf cells and chloroplast cell of mutant was also correspondingly higher. Under intense light condition, the H2O2 content of chloroplast in mutant was less than that in the wild type. [Conclusion] The higher activity of scavenging active oxygen can relieve the photooxidative damage made by excessive light energy of intense light on photosynthetic membrane, which is an important reason for higher photosystem Ⅱ (PS II) stability of this mutant.     

Heredity and gene mapping of a novel white stripe leaf mutant in wheat

Spotted leaf(spl) mutant is a type of leaf lesion mimic mutants in plants. We obtained some lesion mimic mutants from ethyl methane sulfonate(EMS)-mutagenized wheat(Triticum aestivum L.) cultivar Guomai 301(wild type, WT), and one of them was named as white stripe leaf(wsl) mutant because of the white stripes on its leaves. Here we report the heredity and gene mapping of this novel wheat mutant wsl. There are many small scattered white stripes on the leaves of wsl throughout its whole growth period. As the plants grew, the white stripes became more severe and the necrotic area expanded. The mutant wsl grew only weakly before the jointing stage and gradually recovered after jointing. The length and width of the flag leaf, spike number per plant and thousand-grain weight of wsl were significantly lower than those of the WT. Genetic analysis indicated that the trait of white stripe leaf was controlled by a recessive gene locus, named as wsl, which was mapped on the short arm of chromosome 6 B by SSR marker assay. Four SSR markers in the F_2 population of wsl×CS were linked to wsl in the order of Xgpw1079–Xwmc104–Xgwm508-wsl–Xgpw7651 at 7.1, 5.2, 8.7, and 4.4 c M, respectively and three SSR markers in the F_2 population of wsl×Jimai 22 were linked to wsl in the order of Xgwm508–Xwmc494–Xgwm518-wsl at 3.5, 1.6 and 8.2 c M, respectively. In comparison to the reference genome sequence of Chinese Spring(CS), wsl is located in a 91-Mb region from 88 Mb(Xgwm518) to 179 Mb(Xgpw7651) on chromosome 6 BS. Mutant wsl is a novel germplasm for studying the molecular mechanism of wheat leaf development.     

Construction and Virulence of Filamentous Hemagglutinin Protein B1 Mutant of Pasteurella multocida in Chickens

Pasteurella multocida, a Gram-negative nonmotile coccobacillus, is the causative agent of fowl cholera, bovine hemorrhagic septicemia, enzoonotic pneumonia and swine atropic rhinitis. Two filamentous hemagglutinin genes, fhaB1 and JhaB2, are the potential virulence factors. In this study, an inactivationfhaB1 mutant ofP. multocida in avian strain C48-102 was constructed by a kanamycin-resistance cassette. The virulence of thefhaB1 mutant and the wild type strain was assessed in chickens by intranasal and intramuscular challenge. The inactivation offhaB1 resulted in a high degree of attenuation when the chickens were challenged intranasally and a lesser degree when challenged intramuscularly. ThefhaB1 mutant and the wild type strain were investigated their sensitivity to the antibody-dependent classical complement-mediated killing pathway in 90% convalescent chicken serum. ThefhaB1 mutant was serum sensitive as the viability has reduced between untreated serum and heat inactivated chicken serum （P〈0.007）. These results confirmed that FhaB1 played the critical roles in the bacterial pathogenesis and further studies were needed to investigate the mechanism which caused reduced virulence of the fhaB1 mutant.     

Genetic Analysis of Distorted Segregation Ratio of Mating Types Among Basidiospores in Lentinula edodes

This study prepared 17 strains of Lentinula edodes, including wild and cultivated strains as materials, and statistically analyzed the ratios of spores from different aspects via mating types＇ analysis and the OWE-SOJ technique. The results from this study first systematically identified skewed expected distribution of mating-type factors segregation in Lentinula edodes spores has commonly statistical meanings in wild and cultivated strains. Genetic analysis of positive and negative parental-recombined fruiting showed that the nuclear type of F1 progeny spores among those strains segregated through theoretical distribution mainly depended on the combined state of parental dikaryons, and the predominant spores were those with the mating type identical to the dikaryotic parent, indicating that the genetic basis of segregation distortion of spores is different from that of protoplast monokaryons in which the B factor takes predominant responsibility for that phenomenon, and it cooperates A factor with B factor to influence the ratio of spores.     

Quantitative Trait Loci for Grain Chalkiness and Endosperm Transparency Detected in Three Recombinant Inbred Line Populations of Indica Rice

Quantitative trait loci(QTL) for percentage of chalky grain,degree of chalkiness,and endosperm transparency were detected using 3 recombinant inbred line populations derived from crosses between parental lines of commercial three-line hybrids of indica rice.Two of the populations showed great variations on heading date,and the other had a short range of heading date variation.A total of 40 QTLs were detected and fell into 15 regions of 10 chromosomes,of which 5 regions were detected for 1 or more same traits over different populations,2 were detected for different traits in different populations,3 were detected for 2 or all the 3 traits in a single population,and 5 were detected for a single trait in a single population.Most of these QTLs have been reported previously,but a region located on the long arm of chromosome 10 showing significant effects in all the 3 populations has not been reported before.It was shown that a number of gene cloned,including the Wx and Alk for the physiochemical property of rice grain,and GW2,GS3 and GW5 for grain weight and grain size,could have played important roles for the genetic control of grain chalkiness in rice,but there are many more QTLs exerting stable effects for rice chalkiness over different genetic backgrounds.It is worth paying more attentions to these regions which harbor QTL such as the qPCG5.2/qDC5.2/qET5.2 and qPCG10/qDC10/qET10 detected in our study.Our results also showed that the use of segregating populations having high-uniform heading date could greatly increase the efficiency of the identification of QTL responsible for traits that are subjected to great environmental influence.     

Linkage and association mapping of wild soybean (Glycine soja) seeds germinating under salt stress

Salinity threatens soybean germination,growth and production.The germination stage is a key period in the life of soybean.Wild soybean contains many genes related to stress resistance that are valuable resources for the genetic improvement of soybean.To identify the genetic loci of wild soybean that are active during seed germination under salt stress,two populations,a soybean interspecific hybrid population comprising 142 lines and a natural population comprising 121 wild soybean accessions,wer...     

Influences of Mo on Nitrate Reductase,Glutamine Synthetase and Nitrogen Accumulation and Utilization in Mo-Efficient and Mo-Inefficient Winter Wheat Cultivars

The objective is to study whether the accumulation and utilization of plant N are controlled by Mo status in winter wheat cultivars. Mo-efficient cultivar 97003 （eft） and Mo-inefficient cultivar 97014 （ineff） were grown in severely Mo-deficient acidic soil （Tamm-reagent-extractable Mo 0.112 mg kg^-1） with （＋Mo） and without （-Mo） the application of 0.13 mg kg^-1 Mo. The accumulation and use efficiency of plant total N were significantly higher in ＋Mo than that in -Mo and in eft than that in ineff under Mo deficiency. N use efficiency was remarkably higher in maturity but it was forwarded to jointing stage after Mo supply, thus indicating that Mo supply promoted the N use efficiency besides N uptake and eff was efficient in N uptake and utilization. The overall activity of nitrate reductase （NR, EC 1.6.6.1） was significantly higher in ＋Mo than in -Mo and ratio of ＋Mo/-Mo was even to 14.8 at filleting stage for ineff. Activity of glutamine synthetase （GS, EC 6.3.1.2） was significantly lower in ＋Mo than in -Mo. Concentration of nitrate and glutamate were also significantly lower in ＋Mo than in -Mo, thus provided evidences for enhancing N use efficiency by Mo supply. Activities of NR and GS were significantly higher and concentrations of nitrate and glutamate were significantly lower in eff than ineff under Mo deficiency, thus indicated eff was more efficient in N reduction and utilization. It is therefore concluded that Mo could promote N accumulation and utilization in winter wheat which was directly related to NR and feedback regulated by GS. Higher Mo status also results in higher accumulation and utilization of plant N in eft.     

球孢白僵菌硝酸还原酶缺陷型突变体的筛选与鉴定

分别利用甲基磺酸乙酯(EMS)诱变原生质体和用氯酸盐培养基(WAC)诱变菌丝,获得球孢白僵菌硝酸还原酶缺陷型突变体。EMS诱变得到突变体68株,其中硝酸盐还原酶活性最低的突变体相比于野生型菌株活性降低了63.49%。WAC方法诱变获得突变体菌株19株,其中硝酸盐还原酶活性最低的突变体比野生型菌株活性降低了59.46%。     

黄瓜硝酸还原酶cDNA片段的克隆及其在缺氮胁迫下的表达

以黄瓜叶片总RNA为模板,应用逆转录—聚合酶链式反应(RT-PCR),首次扩增出黄瓜硝酸还原酶(NR)cDNA部分片段。经过测序和同源性分析表明:该基因片段长度为395 bp,与GenBank上所登录的笋瓜NR基因同源性达89%,根据所测序列推导该片段由131个氨基酸残基组成。进一步检测其在缺氮胁迫下的活性和表达变化,结果表明缺氮胁迫下硝酸还原酶的活性和表达都明显下降,推测黄瓜NR在转录水平上调节其活性。     

稻恶苗病菌抗感多菌灵菌株的nit突变株形成

从江苏、河北、上海等地采集的水稻恶苗病株上分离到抗、感多菌灵的稻恶苗病菌菌株中，选用７个抗性菌株和６个敏感菌均获得氯酸盐的硝酸盐利用缺陷突变体。     

叶面喷施锌肥对生菜各器官中硝酸盐含量和硝酸还原酶活性的影响

通过田间试验和室内化学分析,研究了叶面喷施锌肥对生菜各器官中硝酸盐含量和硝酸还原酶活性的影响。结果表明,叶面喷施锌肥浓度为0.05%时,生菜中硝酸盐含量最低,硝酸还原酶活性最高,地上部生物量也最高;生菜的各组织器官中硝酸盐的分布趋势均为根>茎>叶,硝酸还原酶活性则表现为叶>茎>根。     

甘蔗对锈病的抗性遗传与育种策略──Ⅰ．F_1群体对锈病抗性的分析

以甘蔗２０个杂交组合的实生苗为试验材料,在田间自然诱发条件下,按０－９级抗感分级标准分析了甘蔗Ｆ１群体对锈病的抗性．结果表明：２０个家系实生苗对锈病抗性分离较大,普遍呈现偏向抗锈级别的偏态分布．根据χ２测验所显示的４种抗锈频次分布型,提出了选择抗锈单株的相应策略．从后代群体的抗病表现评价亲本组合,初步认为新台糖１号×崖８４—１５３、ＣＰ７２／１２１０×崖７１－３７４、ＣＰ７２／１２１０×川５７—４１６和ＣＰ５７—６１４×川５７—４１６为抗锈性强的组合．     

The Growth Effect of Enhanced Ammonium Nutrition on Maize

The two maize varieties,Yuanzheng-808(astrictive type)and Sidan-19(explanate type),were cultured in pots.There were six treatments which the proportion of NO3^-N and NH4^ -N were 1:0(treatment 1),2:1(treatment2),1:1(treatment 3),1:2(treatment 4),0:1(treatment 5)and CK9No nitrogen)respectively.After emergence of seedings,the samples were picked up per 20 days in the growth period and measured chlorophyll contentsnitrate reductase(NR) activity,the weight of dry matter and single plant seed yield respectively.The result showed that enhanced ammonium nutrition(EAN)may increase chlorophyll content,dry matter weight and single plant seed yield.But there was a difference between varieties.To Yuanzheng-808,treatment 2 was the highest yield in all treatments;but treatment 4 was the highest yield to Sidan-19.     

转FRO2基因番茄突变体的抗缺铁黄化特性

为了增加植物的抗缺铁黄化能力,研究了转FRO2基因番茄突变体抗黄化特性．结果显示FRO2基因转化番茄后,使生长在缺铁胁迫下的植株根系铁还原酶活性大大增强（转FRO2基因番茄植株根系酶活性是对照2倍）,番茄铁吸收能力和有效铁还原能力大大加强,植株中有效铁含量增加（转FRO2基因番茄植株叶片有效铁含量是时照的1．5倍）,转FRO2基因番茄的植株叶片颜色显著比对照绿,黄化程度减轻,黄化指数降低（对照的黄化指数是转FRO2基因番茄的1．3倍）,植株生长量显著高于对照（转基因植株株高高于对照50％）．在正常条件下,转FRO2基因番茄根系的FRO2基因表达量增加,铁还原酶活性增加了1．75倍,转FRO2基因番茄植株叶片有效铁含量是对照植株的2倍,是其他耐贮藏转基因番茄的（转反义NR、ACC、CTR1基因）2～3．5倍以上．     

缺氮、磷、钾、钙、镁对芥蓝硝酸盐积累、硝酸还原酶和过氧化物酶活性的影响

缺素试验表明,缺镁促进芥蓝叶片内硝酸盐的积累,缺乏其它元素则减少硝酸盐的积累缺素亦影响硝酸还原酶活性,缺氮、磷、钾、钙均抑制叶片的硝酸还原酶活性,缺镁促进硝酸还原酶活性氮、磷、钾、钙、镁用量适宜,过氧化物酶活性较低缺乏其中任何一个元素均提高了芥蓝叶片的过氧化物酶活性     

增铵营养对玉米生长发育的影响

测试了增铵营养对玉米生长发育的影响。利用盆栽,选用收敛型的玉米远征808和平展型的玉米四单19两个品种做试验材料,在氮素水平一致的条件下,设N03--N和NH4+-N比例分别是1∶O(处理1),2∶1(处理2).1∶1(处理3),1∶2(处理4),0∶1(处理5)及CK(不施氮)6个处理。玉米苗期后在生育期间每20d左右取样1次,测定株高、硝酸还原酶活性(NR)、叶绿素含量、叶面积、干物重,收获后烤种测产。结果不表明,增加根际NH4+-N可提高玉米叶绿素含量、干物质的积累量、提高子粒产量,且不同类型玉米对不同氮素形态比例需求不同,远征808在NO3-—N和NH4+—N比例为2∶1,四单19在NO3-—N和NH4+—N比例为1∶2时干物重和单株产量最高。     

不同生物制剂处理对烤烟打顶后碳氮代谢关键酶活性和Inv/NR比值的影响

采用不同生物制剂处理对打顶后烤烟烟叶中碳氮代谢关键酶硝酸还原酶(Nitrate reductase,NR)、转化酶(invert-ase,Inv)和淀粉酶(amylase,AM)活性变化以及Inv/NR比值进行了研究。结果表明:施加生物制剂在一定程度上提高了叶片中NR、Inv和AM酶活性,增强了叶片的碳氮代谢,刺激上部叶扩展开片,各个处理间碳氮代谢调节效果表现为T1>T2>T3;施加生物制剂10 d后Inv/NR比值开始较CK高,中下部叶T3处理在成熟后期Inv/NR比值过高,对烟叶品质不利,T1和T2处理后氮代谢向碳代谢的转化较CK晚,上部叶碳氮代谢的减弱缓慢,延长了烟叶的成熟时间。综上所述,T1处理对碳氮代谢的调节效果最好,T2其次,T3最差。