A Comparative Study on the Quality Components Between Self Pollinated Seeds and Naturally Pollinated Seeds in Brassica napus L. in Sichuan Ecological Region

[ Objective] This study was to reveal the differences in crude fat and glucosinolates between self pollinated seeds and naturally pollinated seeds in Brassica napus in sichuan ecological region.. [ Method] Near-infrared spectroscopy method （NIRS） was employed to measure the quality components in self pollinated seeds and naturally pollinated seeds of 861 shares of Brassica napus from Sichuan ecological region. And correlation analysis and regression analysis were conducted based on the experimental data via SPSS （statistics package for social science）. [ Result] The contents of crude fat in the self pollinated seeds were commonly a higher than that in the naturally pollinated seeds at 0.01 significant level; while the contents of glucosinolates in the self pollinated seeds and the naturally pollinated seeds were insignificantly different. Both the correlation relationship and linear regression for the crude fat between the self pollinated seeds and naturally pollinated seeds reached the significant level. The regression equations for the contents of crude fat（y1 ） and glucosinolates（ y2 ） in the naturally pollinated seeds and of crude fat（ x1 ） and glucosinolates（ x2 ） in self pollinated seeds were respectively determined to be y1 = 16.844 ＋0.614x1 and y2 = -0.620 ＋ 1.017 x2. [ Conclusion] In Brassica napus breeding, crude fat in naturally pollinated seeds should be emphatically taken into account, meanwhile concurrently considering that in self pollinated seeds; while glucosinolates in both the self pollinated seeds and the naturally pollinated seeds must be simultaneously concerned.

BnaWRKY75 positively regulates the resistance against Sclerotinia sclerotiorum in ornamental Brassica napus

With the development of tourism at home and abroad,Rapeseed(Brassica napus)has become an important ornamental plant.However,its ornamental value at the inflorescence stage is greatly reduced by Sclerotinia sclerotiorum.Identification of important genes in the defense responses is critical for molecular breeding,which is an important strategy for controlling the disease.In this study,we isolated a B.napus WRKY transcription factor gene,BnaWRKY75.BnaWRKY75 was found to encode a nucleus-localized protein and exhibited relatively high expression in the stems.Arabidopsis thaliana transgenic plants expressing BnaWRKY75 showed enhanced resistance to S.sclerotiorum,and both ProBnaWRKY75:GUS and gene expression analyses showed that BnaWRKY75 was highly responsive to S.sclerotiorum infection,indicating the involvement of BnaWRKY75 in response to this infection.Furthermore,overexpression(OE)of BnaWRKY75 in B.napus significantly enhanced the resistance to S.sclerotiorum,whereas the resistance was reduced in RNAi transgenic B.napus plants.Moreover,the BnaWRKY75-OE B.napus plants exhibited constitutive activation of salicylic acid-,jasmonic acid-,and ethylene-mediated defense responses and the inhibition of both H_(2)O_(2)and O_(2)·^(-)accumulation in response to this pathogen.By contrast,BnaWRKY75-RNAi plants showed a reverse pattern,suggesting that BnaWRKY75 is involved in hormonal signaling pathways and in the control of reactive oxygen species accumulation.In conclusion,these data indicate that BnaWRKY75,a regulator of multiple defense responses,positively regulates resistance against S.sclerotiorum,which may guide the improvement of resistance in rapeseed.

Landscape of Sequence Variations in Homologous Copies of FAD2 and FAD3 in Rapeseed(Brassica napus L.)Germplasm with High/Low Linolenic Acid Trait

Genetic manipulation(either restraint or enhancement)of the biosynthesis pathway ofα-linolenic acid(ALA)in seed oil is an important goal in Brassica napus breeding.B.napus is a tetraploid plant whose genome often har-bors four and six homologous copies,respectively,of the two fatty acid desaturases FAD2 and FAD3,which con-trol the last two steps of ALA biosynthesis during seed oil accumulation.In this study,we compared their promoters,coding sequences,and expression levels in three high-ALA inbred lines 2006L,R8Q10,and YH25005,a low-ALA line A28,a low-ALA/high-oleic-acid accession SW,and the wildtype ZS11.The expression levels of most FAD2 and FAD3 homologs in the three high-ALA accessions were higher than those in ZS11 and much higher than those in A28 and SW.The three high-ALA accessions shared similar sequences with the pro-moters and CDSs of BnFAD3.C4 and BnFAD3.A3.In A28 and SW,substitution of three amino acid residues in BnFAD2.A5 and BnFAD2.C5,an absence of BnFAD2.C1 locus,and a 549 bp long deletion on the BnFAD3.A3 promoter were detected.The profile of BnFAD2 mutation in the two low-ALA accessions A28 and SW is different from that reported in previous studies.The mutations in BnFAD3 in the high-ALA accessions are reported for thefirst time.In identifying the sites of these mutations,we provide detailed information to aid the design of mole-cular markers for accelerated breeding schemes.

Effect of Foliar Fertilizer Spraying at Seedling Stage on the Growth Physiological Characteristics and Yield of Brassica napus L.

In order to select a suitable foliar fertilizer for Brassica napus L.at the seedling stage,using‘Fengyou 958’as the material,different foliar fertilizers including BR,Se,Si,BR+Si,BR+Se,Se+Si and BR+Se+Si were sprayed at the seedling stage to study their effect on the physiological characteristics,growth and yield of Brassica napus L..The results showed that the growth,chlorophyll content,soluble sugar content,soluble protein content,and yield of different treatments at the budding stage improved compared with the control.The effect of the Si+Se treatment was the best,followed by the Se and Si treatments.The chlorophyll content of the flower decreased continuously during the whole flowering period,and the chlorophyll content of the mature silique peel was higher than that of the seed.The content of soluble sugar in flowers was the highest in the early flowering stage,and the content of soluble sugar in leaves at the flowering stage was higher than that at the budding stage.The soluble sugar content in the harvested silique peel decreased gradually with the increase of time,and that in the silique peel and seed was similar at 35 d after pollination.The soluble protein content in the silique peel and seed decreased gradually at the mature stage,and the soluble protein content in the silique peel was higher than that in the seed at the same stage.Si+Se foliar fertilizer spraying at the seedling stage can promote the growth and yield of Brassica napus L.and can be applied in Brassica napus L.production.

Development of a KASP Marker on Chromosome A05 for Seed Oil Content of Brassica napus

In order to identify the molecular markers that can be widely used in the breeding of Brassica napus L.varieties with high seed oil content under different genetic backgrounds,we developed a Kompetitive Allele Specific PCR(KASP)marker for seed oil content on the basis of the results from available studies.The verification in the F_(2) population showed that the marker was closely linked to the quantitative trait locus(QTL)for oil content on chromosome A05.The findings helped to breed the‘Fengyou’varieties with high seed oil content in the middle reaches of the Yangtze River.

Recurrent Selection for Improving Quality Characters of Male Sterile Restorer Lines of Brassica napus

[Objective] This study aimed to improve the quality characters of the male sterile restorer lines of Brassica napus by recurrent selection. [Method] The dominant male sterile alleles were used as outcross medium to be transformed with the favourable genes from thirteen materials, and finally excellent restorer materials were bred by recurrent selection. After that, the genetic diversity, genetic gains, fatty acid chain length and unsaturarion ratios of the improved populations were analyzed. [Result] The genetic diversity and genetic gains were obviously improved by the recurrent selection. Nine materials whose oil content exceeding 50% and 14 materials whose protein content exceeding 30% were acquired, and crossed with sterile lines. The comparative experiment showed that there were 11 combinations whose oil content was obviously enhanced compared with the control. [Conclusion] Recurrent selection is an effective way to improve the quality characters of the objective pop- ulations and breed favourable male sterile restorer lines of B. napus.

Establishment on Isolated Microspore Culture Optimized System for Restorer of New Cytoplasmic Male Sterile (NER) of Brassica napus L.

[Objective]The aim was to establish optimized system for NER isolated microspore culture of Brassica napus L.. [Method]Twenty varieties of NER of Brassica napus were grown under uncontrolled temperature and light conditions,and their isolated microspore from anthers were used as explants in vitro culture. The influencing factors of microspore culture were preliminarily studied. [Result]The difference of genotypes was important influencing factors to embryoid yield. The embryoid yield increased by supplementing with 6-BA and NAA,culturing in solid-liquid double layer medium with activated charcoal; The difference was not significant of embryoid yield between culturing in medium supplemented with colchicines and the CK. The rates of cotyledonous embryoids directly developed into normal plantlets increased through enriching with 0.1-0.2 mg/L NAA and being treated on slim illumination two days before being inducted into normal plantlets. [Conclusion]The technical system of microspore culture of restorer of new cytoplasmic male sterile （NER） was established,which and lays a foundation for accelerating genotype purification of NER introgressive line.

Heterogeneous expression of stearoyl-acyl carrier protein desaturase genes SAD1 and SAD2 from Linum usitatissimum enhances seed oleic acid accumulation and seedling cold and drought tolerance in Brassica napus

Flax(Linum usitatissimum L.)is a versatile crop and its seeds are a major source of unsaturated fatty acids.Stearoyl-acyl carrier protein desaturase(SAD)is a dehydrogenase enzyme that plays a key role in oleic acid biosynthesis as well as responses to biotic and abiotic stresses.However,the function of SAD orthologs from L.usitatissimum has not been assessed.Here,we found that two LuSAD genes,LuSAD1 and LuSAD2,are present in the genome of L.usitatissimum cultivar‘Longya 10’.Heterogeneous expression of either LuSAD1 or LuSAD2 in Arabidopsis thaliana resulted in higher contents of total fatty acids and oleic acid in the seeds.Interestingly,ectopic expression of LuSAD2 in A.thaliana caused altered plant architecture.Similarly,the overexpression of either LuSAD1 or LuSAD2 in Brassica napus also resulted in increased contents of total fatty acids and oleic acid in the seeds.Furthermore,we demonstrated that either LuSAD1 or LuSAD2 enhances seedling resistance to cold and drought stresses by improving antioxidant enzyme activity and nonenzymatic antioxidant levels,as well as reducing membrane damage.These findings not only broaden our knowledge of the LuSAD functions in plants,but also offer promising targets for improving the quantity and quality of oil,and the abiotic stress tolerance of oil-producing crops,through molecular manipulation.

Knock-out of BnHva22c reduces the susceptibility of Brassica napus to infection with the fungal pathogen Verticillium longisporum

Verticillium longisporum(Vl43)is a soilborne hemibiotrophic fungal pathogen causing stem striping on oilseed rape(OSR)and severe yield losses.Breeding for resistant varieties is the most promising approach to control this disease.Here,we report the identification of Hva22c as a novel susceptibility factor and its potential for improving OSR resistance.Hva22c is a member of the Hva22 gene family,originally described for barley(Hordeum vulgare).Several Hva22 members have been located at the endoplasmic reticulum.Hva22c is up-regulated in response to Vl43 in both Arabidopsis and OSR.We demonstrate that knock-out of Hva22c in OSR by CRISPR/Cas9 and its homolog in Arabidopsis by T-DNA insertion reduced plants’susceptibility to Vl43 infection and impaired the development of disease symptoms.To understand the underlying mechanism,we analysed transcriptomic data from infected and non-infected roots of hva22c knock-out and wild type plants.We identified a homozygous mutant with frame-shifts in all four BnHva22c loci displaying a vastly altered transcriptional landscape at 6 dpi.Significantly,a large set of genes was suppressed under mock conditions including genes related to the endomembrane systems.Among the up-regulated genes we found several defense-related and phytohormone-responsive genes when comparing mutant to the wild type.These results demonstrate that Hva22c is functionally required for a fully compatible plant-fungus interaction.Its loss of function reduces plant susceptibility,most likely due to endoplasmatic reticulum and Golgi dysfunction accompanied by additionally activated defense responses.These findings can help improve OSR resistance to V.longisporum infection.

The influence of Lactobacillus plantarum fermentation in selenium-enriched Brassica napus L.:changes in the nutritional constituents,bioactivities and bioaccessibility

Selenium(Se)-enriched Brassica napus L.is a valuable organic Se supplement.In this study,the fermentation broth enriched with organic Se(FFS)was prepared using Lactobacillus plantarum to ferment the substrate of Se-enriched Brassica napus L.Significant increases were observed after fermentation in total sugars,reducing sugars,soluble proteins,total phenolic content(TPC),and total flavonoid content(TFC).The organic Se was retained at a concentration of 54.75 mg/g in the freeze-dried sample.Principal component analysis and cluster analysis showed good separation between the FFS and unfermented(FS)groups.Fragrant 2-ethyloxetane had the highest content among all volatiles,while sinapine had the highest content among all phenolic compounds.The fermentation process showed remarkable improvement in the abundance and concentration of volatile compounds and phenolic contents,making FFS exhibit strong antioxidant activity and inhibitory capacity againstα-glucosidase activity.The bioaccessibility of phenolic compounds was significantly greater in FFS compared to FS.ADMET analysis revealed that the majority of phenolic compounds contained in FFS did not exhibit mutagenicity toxicity,hepatotoxicity,skin sensitization,or blood-brain barrier penetration,indicating a favorable level of biosafety.Overall,our study provides a new insight into the further utilization of Se-enriched Brassica napus L.in foods.

Phytogenetic Studies on Intergeneric Hybridization Between Brassica napus and Matthiola incana

The intergeneric hybridization between Brassica napus L. cv. oro and Matthiola incana (L.) R. Br. was carried out to study the phytogenetic peculiarities of the hybrid plants. In order to improve the oil quality of rape seed, ovaries of B. napus pollinated with pollen of M. incana, were cut off and inoculated onto MS media supplemented with various plant hormones at the 7th day after pollination. Two mature embryos were obtained from 750 pollinated ovaries cultured in vitro. The percentage of seed set was 0.26%. The mature embryos were transferred onto the MS media supplemented with 2.0 mg/L 6-BA + 0.1 mg/L NAA, and a compound bud was produced later. The compound bud was then cut into a number of single buds, which were transferred onto fresh media. Twenty-two plantlets in vitro were developed from the above single buds. The hybrid plants (F-1) were basically intermediate between the two parents in many,characters with a few showing hybrid vigor. The fertility of hybrid plants (F-1) was poor. Cytological studies revealed that the hybrid plants (F-1) were mixoploid. in nature. The chromosome number of many somatic cells was 2n = 26, which was the sum of the chromosome number of the two parents. The chromosome number of other somatic cells was 2n = 38, similar to that of B. napus. The hybrid offspring (F-2) from the selfed hybrid plants (F-1) showed polymorphism. Among the hybrid offspring (F-2) some were nearly matroclinous and fertile, similar to B. napus. some others were intermediate between the two parents and less fertile, and a few were poorly developed and nearly infertile. From the hybrid offspring a few plants with improved seed-oil quality were obtained.

Screening of Drought-tolerant Brassica napus L.Varieties and Analysis on Their Physiologic and Biochemical Variations under Drought Stress

[Objective] The aim of this study was to screen drought-tolerant Brassica napus L. germplasm resources by analyzing their physiological and biochemical changes under drought stress. [Method] Forty varieties of B. napus varieties were cultured under PEG-6000 osmotic stress and extreme drought stress in pots, re- spectively. Then, the contents of chlorophyll, carotenoid, proline, malondialdehyde （MDA）, soluble sugar, soluble protein, and the activities of superoxide dismutase （SOD）, catalase（CAT）, peroxidase（POD） were measured under drought stress. [Result] Sever- al drought-tolerant varieties of B. napus were screened out： YAU200908, Xiangyou No.15, YAU200903, YAU200907, YAU200906 and YAU200904. Physiological and biochemical analysis showed that, the contents of chlorophyll and carotenoid de- creased with drought stress increasing; the contents of proline, soluble sugar, solu- ble protein, MDA and the activities of SOD,CAT, POD raised with drought stress in- creasing. [Conclusion] In the rapeseed varieties with stronger drought tolerance, the decrease in carotenoid content and the increase in proline content, soluble sugar content, MDA content, SOD activity, CAT activity were more obvious, so all these physiological and biochemical indices can be used to evaluate the drought tolerance of rapeseed.

Cloning of Brassica napus EIN3 Gene and Its Expression Induced by Sclerotinia sclerotiorum

[Objective] The study was to investigate roles of Brassica napus EINB in （ BnEIN3 ） resistance to Sclerotinia sclerotiorum. [ Methods] Genomic PCR and RT-PCR were carded out to isolate genomic DNA and cDNA sequences of BnEIN3 from oilseed rape, based on the highly conserved region of EIN3 gene from Arabidopsis thaliana and the homologous sequences of oilseed rape ESTs. Expression levels of BnEIN3 were detected in three varieties of oilseed rape inoculated with S. sclerotiorum by real-time quantitative PCR.[Results] A 1 947 bp DNA fragment was obtained from oilseed rape. The fragment shared 82% identity to A. thaliana EIIV3, encoded 614 amino acids containing an EIN3 domain, and was named as BnEIN3. Real-time PCR results showed that expression patterns of BnEIN3 were drastically different in different varieties. In highly resistant oilseed rape variety D083, BnEIN3 expression level was significantly increased 72 h after S. sclerotiorum inoculation whereas in middle resistant and susceptible varieties Zhongshuang 9 and 84039, BnEIN3 expression was suppressed. [ Conclusion ] BnEIIV3 may play an important role in oilseed rape resistance to S. sclerotiorum.

Transcriptional Regulation of 10 Mitochondrial Genes in Different Tissues of NCa CMS System in Brassica napus L. and Their Relationship with Sterility

Northern blot analysis was conducted with mitochondrial RNA from seedling leaves, floral buds, and developing seeds of NCa CMS, maintainer line and fertile F1 using ten mitochondrial genes as probes. The results revealed that 9 out of the 10 mitochondrial genes, except for atp6, showed no difference in different tissues of the corresponding materials of NCα CMS system and that they might be constitutively expressed genes. Eight genes, such as orf139, orf222, atpl, cox1, cox2, cob, rm5S, and rm26S, showed no difference among the three tissues of all the materials detected. So the expression of these eight genes was not regulated by nuclear genes and was not tissue-specific. The transcripts of atp9 were identical among different tissues, but diverse among different materials, indicating that transcription of atp9 was neither controlled by nuclear gene nor tissue-specific. Gene atp6 displayed similar transcripts with the same size among different tissues of all the materials but differed in abundance among tissues of corresponding materials and its expression might be tissue-specific under regulation of nuclear gene. Moreover, three transcripts of orf222 were detected in the floral buds of NCa cms and fertile F1, but no transcript was detected in floral buds of the maintainer line.The transcription of orf139 was similar to that of orf222 but only two transcripts of 0.8 kb and 0.6 kb were produced. The atp9 probe detected a single transcript of 0.6 kb in NCa cms and in maintainer line and an additional transcript of 1.2 kb in fertile F1. The relationship of expression of orf222, orf139, and atp9 with NCa sterility was discussed.

Isolation of the Flanking Sequences Adjacent to Transgenic T-DNA in Brassica napus Genome by an Improved Inverse PCR Method

[Objective] The research aimed to isolate flanking sequences adjacent to the transgenic T-DNA in Brassica napus by an improved inverse PCR method.[Method] Using single clone of transgenic FS4 in Brassica napus as the research materials,total DNA was extracted from transgenic Brassica napus by using modified CTAB method.After enzyme digestion and purification,self-joining was made.Two circles of nested PCR and the sequence alignment were carried out.[Result] A fragement with the size of 4.0 kb was amplified ...

Effect of Main Cultivation Factors on Oil Quality and Stability of Brassica napus Hybrids

[Objective] This study aimed to analyze the influence of five cultivation factors： sowing date, plant density, nitrogen fertilizer amount, phosphate fertilizer amount and potash fertilizer amount on oil quality and stability of Brassica napus hybrids. [Method] Statistical analysis was carried out based on the data from previous studies and our work. [Result] Sowing date had no significant influence on oil quality and stability of B. napus hybrids. The plant density shared a positive correlation with 18-C fatty acid （FA） content, unsaturated fatty acid （UFA） content, total content of linoleic acid and linolenic acid, index of unsaturated fatty acid （IUFA）, so a large plant density can improve the oil quality （by increasing18-C FA content, UFA content, total content of linoleic acid and linolenic acid）, but reduce the oil stability （by increasing IUFA）. The amount of nitrogen fertilizer had no significant influence on the contents of 18-C FA and UFA, but significant positive correlations with the total content of linoleic acid and linolenic acid and IUFA. So, the total content of linoleic acid and linolenic acid can be reduced by increasing nitrogen amount, meanwhile the oil stability was also decreased. Phosphate fertilizer amount did not affect 18-C FA significantly, but was negatively correlated with the UFA content, total content of linoleic acid and linolenic acid, and IUFA. So, increasing the amount of applied phosphate fertilizer can reduce UFA content, total content of linoleic acid and linolenic acid, thereby improving oil stability. Potash fertilizer had no significant influence on the IUFA, a significant positive correlation with 18-C FA content, an insignificant positive correlation with the the UFA content, and a negative correlation with the total content of linoleic acid and linolenic acid. The oil content of rapeseed shared an extremely significant positive correlation with 18-C FA content and UFA content, an negative correlation with the total content of linoleic acid and linolenic acid, and no significant correlation with IUFA. [Conclusion] This study identified the effects of five main cultivation factors on oil quality and stability of B. napus hybrids, and the correlations of oil content with 18-C FA content, UFA content, total content of linoleic acid and linolenic acid, and IUFA.

Molecular Markers and Agronomic Traits of a New Kind of Genic Male Sterile Material Mian 7AB-4-2 in Brassica napus L.

[ Objective] The study was to investigate the agronomic traits and breeding characteristics of genic male sterile material Mian 7AB-4- 2 in Brassica napus. [ Method] The differences in agronomic traits and polymorphisms in SSR markers, between the genic male sterile material Mian 7AB-4-2 in Brassica napus and its sisterly line Mian 7AB-4-1 were investigated by hybridization and molecular identification; and the percentage of sterile individuals of Mian 7AB-4-2 and of the hybrids with its sisterly line Mian 7AB-4-1 from test cross and back cross were also studled. [ Result] Mian 7AB-4-2 was not significantly different in agronomic traits from its sisterly line Mian 7AB-4-1 at 0.05 probability level. The per- centages of sterile individuals in the pollinated fertile Mian 7AB-4-2 plants were over 60%, and that in its sisterly line Mian 7AB-4-1 was about 25%. In test crosses with other nine sterile lines, Mian 7AB-4-1 kept the percentage of sterile individuals of sterile lines over 90%, and the percentage of sterile individuals from back cross over 80%. With regard to molecular markers, Mian 7AB-4-2 and its sisterly line Mian 7AB-4-1 were different in the band number from SSR primers a2 and E10. [ Conclusion] The results indicate that Mian 7AB-4-2 is helpful for rapeseed breeding, quickening the application of new materials in field breeding.

Effects of Nitrogen Fertilizer Management on Biological Traits and Physiological Indexes at Seedling Stage and Yield of Directly-sown Rapeseed(Brassica napus L.)

Field experiments were carried out to study the effects of different nitroge- napplication rates and application times on biological traits and physiological indexes of directly-sown rapeseed （Brassica napus L.） at the seedling stage and investigate the relationship between these biological traits or physiological indexes at the seedling stage and yield, so as to provide scientific theoretical support for high yield and efficient fertilization management in production of winter rapeseed. Field trials were conducted in Chengdu plain of Sichuan Province under rice-rapeseed rotation system during the period of 2011-2012. The nitrogen application rate trial consisted of five nitrogen levels （0, 90, 180, 270 and 360 kg/hm2） and the nitrogen application time trial included NTl（single application as base fertilized）, NT2 （bottom application ＋one time of topdressing at seedling stage） and NT3 （bottom application＋two times of topdressing at seedling stage） under the same nitrogen rate （225 kg/hm2）. The results indicated that compared with no nitrogen application （NO） treatment, the in- crease of nitrogen fertilizer is beneficial to the increase of biological traits including plant height, green leaf number, leaf area index and dry weight of rapeseed at the seedling stage, the improvement of physiological indexes including total nitrogen content, chlorophyll content and soluble protein content of functional leaves, and the reduction of soluble sugar content. Nitrogen rate was linearly correlated with various biological traits at the seedling stage and physiological indexes including total nitro- gen content, chlorophyll content and soluble sugar content in functional leaves over- a/I, but in parabolic correlation with soluble protein content. Under the same nitrogen rate, NT2 treatment exhibited biological traits remarkably or significantly higher than NT1 treatment and NT3 treatment. The nitrogen application times were linearly cor- related with the physiological indexes of functional leaves at the seedling stage. The various biological traits and physiological index of functional leaves at the seedlings stage were in quadratic function parabolic correlation with seed yield, and the corre- lation was significant （P〈0.05）. Therefore, under the rice-rapeseed rotation system in Chengdu plain, the economic rational nitrogen rate is 180-225 kg/hm2, and the mode of bottom application ＋ one time of topdressing （NT2） is suitable.

Abortive Process of a Novel Rapeseed Cytoplasmic Male Sterility Line Derived from Somatic Hybrids Between Brassica napus and Sinapis alba

Somatic hybridization is performed to obtain significant cytoplasmic male sterility （CMS） lines, whose CMS genes are derived either from the transfer of sterile genes from the mitochondrial genome of donor parent to the counterpart of receptor or production of new sterile genes caused by mitochondrial genome recombination of the biparent during protoplast fusion. In this study, a novel male sterile line, SaNa-IA, was obtained from the somatic hybridization between Brassica napus and Sinapis alba. The normal anther development of the maintainer line, SaNa-IB, and the abortive process of SaNa-IA were described through phenotypic observations and microtome sections. The floral organ of the sterile line SaNa-IA was sterile with a shortened filament and deflated anther. No detectable pollen grains were found on the surface of the sterile anthers. Semi-thin sections indicated that SaNa-IA aborted in the pollen mother cell （PMC） stage when vacuolization of the tapetum and PMCs began. The tapetum radically elongated and became highly vacuolated, occupying the entire locule together with the vacuolated microspores. Therefore, SaNa-IA is different from other CMS lines, such as ogu CMS, pol CMS and nap CMS as shown by the abortive process of the anther.

Geometric Modeling of Rape (Brassica napus L.) during Seedling Stage

[Objective] The paper was to study the geometric modeling of rape（Brassica napus L.） during seedling stage.[Method] Based on the analysis and observation of morphological structure and growth process of rape during seedling stage,a characteristic parameters-based three-dimensional mathematical model of rape and its visible method was proposed.The individual control parameters were extracted according to the morphological structures of various organs of rape.Different sizes of leaf and petiole model were constructed by using cubic Bézier surface.The cylinder with different upper and lower bottom area was adopted as the main stem model.Finally,three-dimensional reconstruction of whole Rape plant during seedling stage was achieved through the operations of rotation,scaling and splicing.[Result] This method had certain controllability,which was also easy and convenient,and could quickly use to build the geometric model of rape during seedling stage.[Conclusion] The results provided reference for study on structural model of rape.