Rice planthopper resistance of interspecific protop last fusin line"pf9279" between O.sative and O.officinalis

Ａｎｉｎｔｅｒｓｐｅｃｉｆｉｃｈｙｂｒｉｄｌｉｎｅｐｆ９２７９ｗａｓｏｂｔａｉｎｅｄｂｙｐｒｏｔｏ ｐｌａｓｔｆｕｓｉｏｎｂｅｔｗｅｅｎ０２４２８（ｊａｐｏｎｉｃａ,ｗｉｔｈａｗｉｄｅｃｏｍ ｐａｔｉｂｉｌｉｔｙｇｅｎｅ）ａｎｄＣＮＷ２４０（Ｏ．ｏｆｆｉｃｉｎａｌｉｓ,ｆｒｏｍＭａｌａｙｓｉａ）ａｔＣＮＲＲＩｉｎ１９９２．ＰｏｓｓｉｂｌｅｉｎｔｒｏｇｒｅｓｓｉｏｎｏｆｐｌａｎｔｈｏｐｐｅｒｒｅｓｉｓｔａｎｃｅｆｒｏｍＯ．ｏｆｆｉｃｉｎａｌｉｓｉｎｔｏｐｆ９２７９ｗａｓｉｎｖｅｓｔｉｇａｔｅｄｂｙｆ…     

籼型杂交早稻协优9279的选育与应用

协优９２７９是安徽省杂交早稻选育协作攻关组用协青早Ａ与恢复系Ｒ９２７９配组的籼型杂交早稻新组合。该组合具有熟期早、丰产稳产、米质较优、抗稻瘟性强等优点，适宜在安徽沿江双季稻区作早稻应用。１９９７年通过安徽省农作物品种审定委员会审定并定名为皖稻６５号。     

同源四倍体水稻与非洲栽培稻杂交的效果

以4份同源四倍体水稻(Oryza sativa,2n=4x=48)和4份二倍体水稻(Oryza sativa,2n=2x=24)为母本,以4份非洲栽培稻(Oryza glaberrima,2n=2x=24)为父本进行远缘杂交配组,共配制32个杂交组合。研究结果表明,非洲栽培稻分别与亚洲栽培稻中的两种倍性水平的水稻品系进行杂交均表现出一定的可交配性,生殖隔离并不很严格。然而,不同倍性的亚洲栽培稻与非洲栽培稻杂交,其结实率表现出明显的差异。二倍体水稻与非洲栽培稻不容易杂交,其结实率比较低(0．32％—1．93％),而同源四倍体水稻与非洲栽培稻较容易杂交,其结实率比较高(1．22％—8．86％,)。由此认为,利用同源四倍体水稻为母本与非洲栽培稻杂交更容易将后者的遗传物质引入亚洲栽培稻。     

同源四倍体水稻与非洲栽培稻杂交的胚胎学观察

以同源四倍体水稻(Oryza sativa,2n=4x=48)和二倍体水稻(Oryza Sativa,2n=2x=24)为母本,以非洲栽培稻(Dryza glarri,2n=2x=24)为父本进行远缘杂交配组,对其杂交结实的胚胎学机理进行了研究。结果表明,非洲栽培稻的花粉粒能在二倍体水稻的柱头上萌发,但萌发频率仅为0．18％～0．56％,花粉管在花柱内的伸长速度比较慢,发生受精的频率比较低,因而二倍体水稻与非洲栽培稻杂交的结实率比较低。然而,非洲栽培稻的花粉粒在同源四倍体水稻的柱头上萌发频率高达12．81％～14．65％,花粉管在花柱内的伸长速度比较快,发生受精的频率比较高,因而同源四倍体水稻与非洲栽培稻杂交的结实率比较高。在同源四倍体水稻与非洲栽培稻的杂交中发现,其受精作用比较特殊,其中包括精细胞与卵细胞的单受精作用,精细胞与次生极核的单受精作用和正常的双受精作用,总受精率和总成胚率分别为7．49％～9．28％和6．61％～8．64％。     

RFLP and SSR mapping of a new gene for brown planthopper resistance introgressed from O. Eichingeri into cultivated rice(O. Sativa L.)

Nine brown planthopper(BPH) resistance genes have been registered so far, but of them only Bph1, bph2, Bph3, bph4, Bph9,and other three unregistered genes Bph10(t), Bph(t), bph(t) were located on chromosome 3, 4, 10, and 12, respectively, by using traditional and molecular mapping methods. To use the genes for BPH resistance in rice breeding and production, interspecific hybrids between cultivated rice and accessions of O. eichingeri (2n=24, CC), a wild rice species from Africa, with strong resistance to BPH and whitebacked planthopper were produced.     

Clubroot resistance introgression in interspecific hybrids between Raphanus sativus and Brassica napus

Clubroot is a prevailing soil-borne disease affecting rapeseed production worldwide.However,few clubroot resistant rapeseed accessions were available for breeding.Identification and introgression of new clubroot resistant genes from closely related species by distant hybridization is an effective strategy.In the present study,9 radish(Raphanus sativus L.,2n=18,RR)lines resistant to Plasmodiophora brassicae pathotype 4 were used as donors to transfer clubroot resistance into a susceptible rapeseed(Brassica napus L.,2n=38,AACC)line by distant hybridization combined with embryo rescue.Nine intergeneric crosses were made but only 1(411×93039)produced F1 plants both from embryo rescue and natural seed-setting.Authenticity of triploid F1 hybrids(2n=28,ACR)were verified by flower color,cytological observation and molecular marker analysis,and 2 genuine F1 hybrids were identified.After chromosome doubling,these synthetic allohexaploid plants(2n=56,AACCRR)became partially fertile(pollen viability rate=35%)and were backcrossed with rapeseed parent to generate a BC1 population(2n=47,AACCR).Totally 178 BC1 plants were obtained,of which the majority(96.1%)were resistant to clubroot.These backcrossing progenies could be used for the breeding of new rapeseed varieties resistant to clubroot.     

同源四倍体水稻与非洲栽培稻杂交的后效性研究

利用亚洲栽培稻中的4份同源四倍体水稻(O.sativa,2n=4x=48)和相应的4份二倍体水稻(O.sativa,2n=2x=24)为母本,以4份非洲栽培稻(O.glaberrima,2n=2x=24)为花粉供体进行远缘杂交后,对其杂种后代的分离动态进行了研究.结果表明,不同倍性的普通栽培稻与非洲栽培稻之间杂交后代的结实率以二倍体普通栽培稻的较高.在配制的32个杂交组合中,其杂种第1代群体均表现出明显的营养生长优势.从群体的生长势来看,杂种第2代群体比杂种第1代群体要弱一些;在杂种第2代群体中,以同源四倍体水稻为母本的杂交组合的分离现象比以二倍体水稻为母本的杂交组合的分离现象更明显.在各杂交组合的第3代群体中,从植株的株叶形态和生育期来看,株系间的差异和株系内的变异依然很明显,变异频率更宽,变异种类更多.在普通栽培稻与非洲栽培稻的杂交组合中,育性变异、生长势变异、株叶形态变异、染色体变异和结实性变异等是较易发现的变异现象.     

三系和两系杂交中籼组合间产量优势比较

对供试２１ 个杂交中籼三系组合和两系组合产量优势及构成因素进行了分析比较,表明两系组合产量相对有较高潜力,表现为库大粒多,相对差异极显著,且穗数、结实率并不因穗大而降低。认为三系和两系组合提高产量途径相同之处是要保证穗数,不同之处是三系组合的选育要着眼于增大穗型,提高结实率,两系组合则在大穗基础上增加实粒数,并提高籽重。     

埃塞俄比亚芥和白菜型油菜远缘杂种F1的鉴定

用形态学、细胞学和限制性片段长度多态性分子标记（AFLP）三种方法对埃塞俄比亚芥（Brassica carinata, BBCC, 2n=34）和白菜型油菜（Brassica rapa, AA, 2n=20）远缘杂交的后代进行了鉴定，结果表明，细胞学和分子标记鉴定杂种真实可靠，但试验技术繁琐，形态学鉴定在操作上简单易行，但主观性较强。在实际生产中可结合几种方法同时进行。     

Insecticide resistance and activities of relative enzymes in different populations of the white-backed planthopper

Ｗｈｉｔｅｂａｃｋｅｄｐｌａｎｔｈｏｐｐｅｒ（ＷＢＰＨ）,Ｓｏｇａｔｅｌｌａｆｕｒｃｉｆｅｒａ（Ｈｏｒｖａｔｈ）,ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｄｅｖａｓｔａｔｉｎｇｉｎｓｅｃｔｐｅｓｔｓｏｎｒｉｃｅｉｎＡｓｉａ．Ｉｔｓｃｏｎｔｒｏｌｍａｉｎｌｙｄｅｐｅｎｄｅｄｏｎｔｈｅｃｈｅｍｉｃａｌｐｅｓｔｉｃｉｄｅｓ．Ｓｕｒｖｅｙｓｏｆｉｎｓｅｃｔｉｃｉｄｅｓｕｓｃｅｐｔｉｂｉｌｉｔｙｒｅｖｅａｌｅｄｔｈａｔｏｒｇａｎｏｐｈｏｓ ｐｈｏｒｕｓａｎｄｃａｒｂａｍａｔｅｒｅｓｉｓｔａｎｃｅｈａｓｅｍｅｒｇｅｄｓ…     

Growth and yield potential of Oryza sativa and O. glaberrima upland rice cultivars and their interspecific progenies

A recent breakthrough in generating fertile progeny from Oryza sativa×O. glaberrima crosses gives rice breeders access to a broader range of germplasm. Interspecific crosses might provide new solutions to the low productivity of upland rice systems prone to weed competition. Two field and one pot experiments conducted during 1995 and 1996 served to characterize growth and yield potential of CG14 (O. glaberrima), WAB56-104 (O. sativa) and their progeny. During the 1995 wet season and the 1996 dry and wet seasons, the lines were seeded in a well-drained upland field in Ivory Coast with supplemental sprinkler irrigation. A randomized complete-block design with three replications was used, with cultivar and nitrogen levels as sub-plots. Specific leaf area (SLA), leaf area index (LAI), leaf chlorophyll content (SPAD method) and tiller number were measured at 2-week intervals until flowering. Grain yield and yield components were measured at maturity. In all environments, CG14 produced two to three times the LAI and tiller numbers as WAB56-104. This was associated with a high SLA and low leaf chlorophyll content. Grain yields of CG14 did not respond to N inputs, although the sink potential did. The difference was mainly caused by grain shattering. The progenies had intermediate LAI, SLA and leaf chlorophyll content, but their grain yields, tiller numbers and resistance to lodging and grain shattering were similar to WAB56-104. Across lines, LAI and SLA were significantly correlated. A paddy field experiment confirmed the relationship between LAI and SLA for a wider range of rice cultivars and interspecific progenies. A pot experiment demonstrated that leaf net CO₂ assimilation rates (A_max) followed a common linear function of areal leaf chlorophyll content across cultivars. The main common cause of differential LAI and A_max appeared to have been genotypic patterns of SLA, which might be an important determinant of growth vigor and competitiveness with weeds. The possibility is discussed of combining, in a single line, high SLA during vegetative growth (for weed competitiveness) with low SLA during the reproductive growth phase (for high yield potential), to produce an efficient plant type for low-management conditions.     

Relationship between Shoot Elongation and Dry Matter Weight During Submergence in Oryza sativa L. and O. glaberrima Steud. Rice Cultivars

Abstract

Rice plants are damaged by flash floods with a rapid increase in water level caused by a heavy rain. However, rice plants cope with the flash floods either by an “escape strategy” involving rapid shoot elongation or by a “quiescence strategy” involving surviving under water with minimal activity. As we found in previous experiments, Saligbeli cultivar adapted well to flash floods through rapid shoot elongation. To understand the vigorous growth process during submergence, we studied the relationship between shoot elongation and changes in dry matter weight (DMW) during submergence. O. glaberrima Steud. cv. Saligbeli and O. sativa L. cv. Ballawé and IR 49830-7-1-2-2 were used. Saligbeli and Ballawé exhibit shoot elongation, and IR 49830-7-1-2-2 exhibits flash-flood tolerance due to the presence of the Sub-1 gene. Twelve-day-old seedlings were submerged for 7 days and the plant length and DMW were measured. The plant length ratio of submerged to control plants in Saligbeli was higher than that of other cultivars during 2-6 days of submergence but IR 49830-7-1-2-2 shoot elongation was inhibited by submergence. In all three cultivars, the elongation of the developing leaf sheath conferred shoot elongation during submergence. The plant length of all submerged plants showed a strong positive correlation with DMW of the leaves developed during submergence. Submerged Saligbeli and Ballawé showed strong negative correlations between DMW of the leaves developed before and during submergence (r = –0.786 for Saligbeli and –0.772 for Ballawé , P < 0.05), suggesting that the enhancement of shoot elongation during submergence is accomplished by using dry matter of the leaves developed before submergence. However, the correlation was not observed in the submerged IR 49830-7-1-2-2. Further details from studies using isotopes are also needed to understand the plant growth during submergence.     

对甘蓝与大白菜种间杂交合成的甘蓝型油菜的研究

通过甘蓝与大白菜种间杂交获得了５０个甘蓝型油菜杂交组合。田间抗性鉴定结果：１７个组合抗寒、３８个组合耐热、４个组合抗病毒病、４２个组合抗霜霉病、３９个组合避开了菌核病。合成组合中正常可育的组合２４个,这些品系的自交不亲和性、生物学特性及抗逆性都与的它们的双亲尤其是母本甘蓝相似。正常可育的品系中１９个自交不亲和,与胞质不育则度的３个合成品系中没有找到恢复基因,但它们是理想保持系,其后代不育性彻底而稳     

Insecticide resistance and activities of relative enzymes in different populations of the white backed planthopper

White backed planthopper (WBPH), Sogatella furcifera (Horvath), is one of the most devastating insect pests on rice in Asia. Its control mainly depended on the chemical pesticides. Surveys of insecticide susceptibility revealed that organophosphorus and carbamate resistance has emerged since early 1980s in China and Japan. WBPH has the long distance migration property, and Heinrichs(1994) considered that the migration might influence the resistance level of planthoppers. So we conducted the comparative studies on insecticide susceptibility and activities of resistance relative enzymes in four WBPH populations collected from Zhejiang, Yunnan, and Hainan provinces of China in 1997.     

不同倍性栽培稻与药用野生稻种间杂交不结实性的比较胚胎学观察

以栽培稻(Oryza sativa)品种L202二倍体（L202 2x）及其同源四倍体（L202 4x）作母本分别与药用野生稻（Oryza officinalis）杂交,比较了两个杂交组合的杂交结实性及影响结实性的杂种胚胎发育细胞学。两个杂交组合所取得的一致结果是：杂交授粉后30 d所有杂交小穗均干枯死亡,不能结实;种间杂交不结实的原因在于受精和杂种胚胎胚乳发育异常。两个杂交组合的受精和杂种胚胎胚乳发育虽然均存在双受精、单受精和未受精类型,但就受精率而言,L202 2x作母本的平均总受精率为59.45％,略高于L202 4x（54.87％）; L202 4x的单受精率（24.60％）则高于L202 2x的单受精率（15.30％）。两个杂交组合的杂种胚胎胚乳发育均严重异常,虽然在授粉后1 d形成小的球形胚;到授粉后3 d,胚胎发育停滞并开始解体;至授粉后5 d,只有二倍体杂交组合的极少数胚胎可发育到梨形胚时期,四倍体组合的胚胎则基本全部解体。双受精胚囊内胚乳发育更为异常,在授粉后1 d,游离胚乳核就开始解体退化,到授粉后3 d不能形成细胞化胚乳或细胞化过程异常。与L202 2x作母本的杂交相比,以L202 4x作母本所得杂种胚胎发育更为滞后,且退化严重,形成的游离胚乳核少,解体早,不能进行细胞化。因此,利用同源四倍体栽培稻与药用野生稻杂交获得种间杂种的难度更大。     

Transfer of PLRV resistance fromSolanum verrucosum Schlechdt to potato (S. tuberosum L.) by protoplast electrofusion

Summary Somatic fusions between an accession of the diploid wild speciesSolanum verrucosum and a dihaploid S.tuberosum genotype were produced in order to incorporate resistance to potato leafroll virus (PLRV). In total 15 somatic hybrids out of 16 regenerants were obtained. Identification of hybrids was based on additive RAPD patterns, general morphological characteristics, chromosome numbers and chloroplast counts in stomata guard cells. A field trial was performed with the hybrids, their two parents and the control cultivar Kennebec to assess field performance and phenotypic variability. Yield parameters varied considerably among somatic hybrids. Some of the hybrids gave significantly higher yields, tuber numbers and tuber weights than both parents. Pollen fertility of hybrids ranged from 19 to 77%. Twelve hybrids were found to be resistant to PLRV.     

Bacterial Impact on H2O2 Accumulation during the Interaction between Xanthomonas and Rice

Abstract

Localization of hydrogen peroxide (H₂O₂) accumulation during the interaction between rice and Xanthomonas oryzae pv. oryzae (X. oryzae pv. oryzae) was observed by histochemical analysis and electron microscopy. The changes that occurred in an avrXa7 mutantstrain of X. oryzae pv. oryzae including the decreased production of endogenous H₂O₂, impacted on the mean level of H₂O₂ accumulation during the interaction with the plant. The results of catalase and aminotriazole treatments indicated that the changes of H₂O₂ accumulation during the interaction are induced by the impairment of endogenous H₂O₂ accumulation in X. oryzae pv. oryzae. These results suggested that bacterial pathogen is a potential source of the H₂O₂ accumulated in the interaction between rice and X. oryzae pv. oryzae.