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1.
DNA fingerprinting studies have been carried out with the physiologically mature male and female plants of Jojoba using 80 ISSR primers with a view to generate sex-linked markers. After bulk segregant analysis, two unique ISSR markers, viz. ISSR8481500 and VIS111317 have been developed which can be used for determining the sex at the seedling stage. Of the eighty primers tested on the pooled male DNA and pooled female DNA samples, six ISSR primers were found to be associated with sex expression. Of the six, only two primers ISSR848 and VIS11 generated unique male sex specific bands of ~1,500 and ~1,300 bp which were consecutively present in all the male genotypes and absent in all the respective female genotypes. The remaining four primers when tried on individuals of different genotypes were confined to their sex specificity in only two female genotypes and absent in their male counterparts. One of the male-sex specific markers, VIS111317 has also been cloned and sequenced which showed homology with a sex linked gene, DD44 from dioecious Silene species. Furthermore, VIS111317 was converted into a male sex-specific sequence tagged sites (STS) marker of 584 bp. The male specific STS marker thus developed has been verified and validated on 100 populations of male and female individuals from ten different genotypes of Jojoba to endorse the diagnostic reliability of the STS marker. This can gainfully be employed for screening of sex at seedling stage which would be quite helpful for uprooting the undesired plants, thereby, saving resources like labor, water, fertilizers and space for highly desirable female plants.  相似文献   

2.
Sex type determination in papaya (Carica papaya L.) is very important for crop improvement processes because it accelerates the identification of the fruitful plants. The use of molecular technology provides a quick and reliable identification of sex types in plantlets growing in seedbeds. Random amplified polymorphic DNA (RAPD) markers were used to determine the sex types of Colombian cultivars of dioecious papaya genotypes. This species has three sex types (male, female and hermaphrodite) determined by a multiallelic locus. There are no morphological differences at the chromosome level; therefore the identification of sex types by chromosomal dimorphism is not possible. A RAPD marker of 900 bp was found in male plants, but not in females or hermaphrodites. From this RAPD marker a sequence characterized amplified region (SCAR) was developed and it was possible to amplify fragments from the genomes of male and hermaphrodite plants, but not the female ones. The results indicate that this new SCAR marker will be valuable to determine the sex type of papaya plants.  相似文献   

3.
Summary Hop (Humulus lupulus L.) is dioecious species with female plants of commercial value. During breeding process it is desirable to identify the sex of hop plants at the stage of seedling. Twenty two inter simple sequence repeat (ISSR) primers were screened on female and male hop genotypes of Russian and European origin. Two ISSR primers revealed fragments specific for male plants of hop. Based on the sequences two pairs of primers were designed. These male specific sequence tagged site (STS) markers were tested on male hop accessions of Russian origin and female hop accessions of Russian, European and American origin. A high homology of male specific hop DNA sequences to expressed sequences from EMBL plants EST database was found, most of which code cell wall glycoproteins. The applicability of ISSR-PCR analysis for development of sex molecular markers in hop is discussed.  相似文献   

4.
Buffalograss, Buchloe dactyloides (Nutt.) Engelm, is a dioecious turfgrass native to the Great Plains of North America. Since its naturalization, it has become the most wildly cultivated warm-season turfgrass in northern China. While dioecious plants represent only a small proportion of all plant species, they are important models in the study of plant sex determination and evolution. The identification of the sexes is important in the theory and practice of breeding programs. At present, there is no effective method to determine the sex of early stage buffalograss. The objective of this study was to use sequence-related amplified polymorphism (SRAP) and integrated bulked segregant analysis (BSA) technology to find sex linked markers in B. dactyloides. A total of 228 primer combinations were screened and 2,690 SRAP bands examined. Only ME9/EM2 could generate a specific fragment (~240 bp) in all the female plants, which was absent in male plants. The methods described here provide a simple and reproducible means of early sex identification in B. dactyloides.  相似文献   

5.
Sex identification in Pistacia species during the long juvenile stage is an economically desirable objective. Due to the lack of morphological methods to identify sex at this stage, the application of molecular markers is expected to facilitate breeding programs. The aim of our study was to identify a marker closely linked to sex loci in Pistacia atlantica Desf subsp. mutica, P. khinjuk, and P. vera subsp. Sarakhs. Samples were collected from both male and female plants of each species, and their band patterns were analyzed according to the presence or absence of specific bands. Thirty random amplified polymorphic DNA (RAPD) primers and a pair of sequence characterized amplified region (SCAR) primers were tested as potential markers of sex in wild Pistacia species. Among the RAPD primers, only BC1200 was found to amplify a specific sex band present in female plants. Based on our analysis of all individual samples, a fragment of approximately 300 bp was amplified in female trees but absent in male ones. Although sex determination mechanisms in Pistacia are still unknown, they may be controlled by a single locus that acts as a trigger. The SCAR technique has proved to be a reliable technique in gender determination of pistachio genotypes at the seedling phenophase. This method could reduce both the time and costs associated with breeding programs.  相似文献   

6.
Garden asparagus (Asparagus officinalis L.) is an economically important plant. This species is dioecious, and male plants are considered to be more desirable than females due to their higher yields. To reduce the time required for asparagus breeding, molecular marker techniques have been employed to identify sex-linked DNA markers. In the present study, we converted the male-specific random amplified polymorphic DNA marker T35R54-1600 into a sequence tagged site marker. We cloned a male-specific DNA fragment amplified with the T35R54 primer and determined the sequence of the fragment. The size of T35R54-1600 is 1,586 bp, and this fragment is not homologous to known sex-linked BAC sequences, indicating that this fragment is a new sex-linked region. Within this fragment, we designed the primer pair ‘MSSTS710’ to amplify a 710 bp region. This marker could be used to identify the sex of eight cultivars of A. officinalis: ‘Mary Washington 500W’, ‘UC157’, ‘Harumachi Green’, ‘Super Welcome’, ‘F4’, ‘Pacific 2000’, ‘F2’ and ‘Backlim’. We also analyzed the applicability of this marker to two dioecious Asparagus species, A. schoberioides and A. kiusianus, which are cross-compatible with A. officinalis. Although male-specific DNA fragments of two dioecious Asparagus species, A. schoberioides and A. kiusianus, were generated using the existing male-specific marker Asp1T7sp, no amplicon was obtained using the MSSTS710 marker. Since MSSTS710 can be employed for sex identification only in A. officinalis and not in closely related Asparagus species, the DNA region around the MSSTS710 marker must be variable among Asparagus species.  相似文献   

7.
It is crucial to develop a rapid technique for identifying sexuality in the seedling stage of persimmon (Diospyros kaki Thunb.), and the elimination of male progeny has been regarded as an important strategy for enhancing breeding efficiency. In this study, phenotype characterization and genotyping of the male‐linked OGI marker were carried out using 205 accessions, including persimmon cultivars, F1 progeny and nine related Diospyros species. All persimmon cultivars displayed consistent results regarding OGI amplification and sex phenotype. A total of 143 F1 progeny were derived from 11 crosses, among which 95 individuals had flowered. In the flowering full‐sib families, the amplification of the OGI marker in agreement with the sex phenotype was obtained in 85 plants (89.5%). The segregation of OGI in ‘Huashi 1’ × ‘Luotian Tianshi’ and ‘Huashi 1’ × Male 3 F1 populations fit a 1 : 1 ratio. Furthermore, high OGI transferability was observed in nine related species. Overall, the results indicated that the OGI locus could be used to distinguish male from female persimmon plants at an early stage.  相似文献   

8.
Tomato mosaic virus (ToMV) is an important Tobamovirus that causes significant crop losses. Resistance to the ToMV is conferred by the genes Tm1, Tm2 and Tm2a. Among these three genes, Tm2a confers resistance to most strains of the ToMV. Screening of genetic lines under field conditions based on phenotype is time‐consuming and challenging due to concerns associated with stability of the virus and its potential transmission to other plants. Tightly linked molecular markers associated with resistance genes can improve selection efficiency and avoid these problems. This study developed a PCR‐based marker based on restriction site differences from Tm2a locus‐specific sequences, which was found to be useful in identifying the resistant and susceptible genotypes and was consistent with phenotypic data. The marker is a codominant cleaved amplified polymorphic sequence (CAPS) marker producing 270‐ and 600‐bp DNA fragments from resistant genotypes and an 870‐bp fragment from susceptible genotypes when digested with HaeIII restriction enzyme. This novel marker can be useful for tomato breeders to screen progeny from segregating populations for ToMV resistance.  相似文献   

9.
Late blight caused by Phytophthora infestans is one of the most destructive diseases of tomato (Solanum lycopersicum L.) that mainly occurs in cool and wet environments. With the spread of the A2 mating type and new clonal lineages, fewer fungicides provide effective control of the disease, which has increased its worldwide threat. Host resistance could contribute significantly to sustainable disease control. Ph‐3 is a race‐specific late blight resistance gene commonly used in commercial tomato breeding. Availability of precise and easy to use gene‐based markers would facilitate selection. In this study, a Ph‐3 on‐gene cleaved amplified polymorphic sequence (CAPS) marker, Ph3.gsm/HincII, was developed based on the published gene sequence of Ph‐3. The effectiveness of the marker was evaluated along with other published Ph‐3 markers using an F9 recombinant inbred line (RIL) population derived from NC 23E‐2(93) × L3708. Markers Ph3.gsm/HincII and TG328/BstNI accurately genotyped the RIL population for Ph‐3. In addition, Ph3.gsm/HincII was able to differentiate variable susceptible alleles. This reliable codominant DNA marker would be very useful in marker‐assisted selection, particularly for resistance gene pyramiding.  相似文献   

10.
Papaya is a productive and nutritious fruit grown in tropical and sub-tropical regions worldwide. It is polygamous with three sex types: female, male and hermaphrodite. Sex determination in papaya is controlled by an XY sex chromosome system with two slightly different Y chromosomes, Y for males and Yh for hermaphrodites. Comparative analysis of the hermaphrodite-specific region of Yh chromosome (HSY) and male-specific region of Y chromosome (MSY) revealed 99.6% sequence identity, which explains why DNA markers that amplify for both males and hermaphrodites have easily been developed, but not for the male trait specifically. We examined the 0.4% sequence differences, and found 1887 indels and 21,088 SNPs between MSY and HSY. The vast majority of indels are single nucleotide or few base pairs. A large male-specific retrotransposon insertion of 8396 bp was used to develop two papaya male-specific markers, PMSM1 and PMSM2 that amplify 585 and 548 bp fragments, respectively. These two markers were tested in 11 gynodioecious and four dioecious varieties along with autosomal DNA marker 71E and male/hermaphrodite marker W11, and the results showed clear separation of male from hermaphrodite and female. PMSM1 and PMSM2 were also used to test the sex type of six sex male-to-hermaphrodite reversal mutants which are crucial materials for validating candidate genes for sex determination in papaya. Our result showed all six mutants were positive for the male-specific markers. These male-specific markers can be used to distinguish gynodioecious and dioecious cultivars in papaya seed market, and facilitate genetic and genomic research for papaya improvement.  相似文献   

11.
All cycads are strictly dioecious with a long juvenile stage. Currently, there is no method available to determine the sexuality of seedlings prior to the onset of cone formation. This study aimed to develop a sex specific Random Amplified Polymorphic DNA (RAPD) marker for Encephalartos natalensis. Initially, 140 primers were used to amplify the bulk DNA of five individuals each of known male and female sexuality. While a high degree of polymorphism was observed in the amplification profiles of male and female plants, only primer OPD-20 generated a specific band (∼850 bp) in female DNA. To validate this observation, this primer was re-tested with 69 individuals of E. natalensis. The 850 bp DNA band was present in all 38 female individuals tested and it was consistently absent in all 31 male plants tested. The result offers a rapid and simple test to determine sexuality of E. natalensis seedlings at early stages of development, before the onset of reproductive maturity thereby saving time and economic resources when cultivating these specimens.Electronic Supplementary Material Supplementary material is available to authorised users in the online version of this article at .  相似文献   

12.
Application of AFLP for the detection of sex-specific markers in hemp   总被引：5，自引：0，他引：5  
H. Flachowsky    E. Schumann    W. E. Weber  A. Peil   《Plant Breeding》2001,120(4):305-309
Two dioecious hemp accessions (Can18 and Can17) were tested by bulked segregant analysis for polymorphisms between male and female bulks with amplified fragment length polymorphisms. Thirty‐nine primer combinations were tested and 20 of these yielded one to three male‐specific bands. In contrast, no female‐specific band was detected. Eight of these primer combinations were used for testing 80 progeny plants from a cross between two plants from Can18 and 30 plants from Can17. A total of 16 and 17 male‐specific fragments were obtained for Can 18 and Can 17, respectively. Eleven fragments exhibited the same fragment size in both accessions. All male plants, but not one female plant, showed the respective polymorphic band with each of the eight primer combinations. Problems regarding sex determination under field conditions were successfully overcome by testing plants that had been grown in small pots in a greenhouse. The abundant number of potential markers for the male sex, their complete cosegregation with male plants and the absence of markers for the female sex support the presence of a male sex chromosome in hemp.  相似文献   

13.
Garden asparagus (Asparagus officinalis L.) is an economically-important perennial crop. This plant is dioecious, as there are both male and female individuals; male individuals are preferred over females for agricultural production. To reduce the time required for garden asparagus breeding, various male-specific DNA markers are utilized. Male-specific DNA markers, such as Asp1-T7sp and MSSTS710, are currently available for sex identification in many asparagus cultivars. In the current study, we found that these markers are not suitable for sex identification in the purple asparagus cultivar ‘Pacific Purple’, as male-specific amplification of this marker was detected in some male individuals of this cultivar but not in other males. The Asp1-T7sp marker is suitable for use in sex identification in various Asparagus species related to A. officinalis, indicating that the region around this marker is conserved among these species. Thus, we isolated a DNA fragment around this marker by inverse PCR and produced a new DNA marker, MspHd, based on this sequence. However, like Asp1-T7sp and MSSTS710, MspHd was not suitable for sex identification in the cultivar ‘Pacific Purple’. Since all ‘Pacific Purple’ males have morphologically similar male flowers with functional stamens, we produced a new male-specific marker based on the sex determination gene, MSE1/AspMYB35/AspTDF1, which is responsible for stamen development. This marker, named AspMSD, is suitable for sex identification in ‘Pacific Purple’. In addition, this marker can be utilized for sex identification in various asparagus cultivars and some related Asparagus species.  相似文献   

14.
Seed yield is a major breeding target in tetraploid red clover. We investigated if marker‐assisted parentage analysis can identify progeny plants with two high seed‐yielding parents in tetraploid red clover and if this technique is more advantageous than traditional half‐sib selection. Parentage analysis was successfully performed on the progeny from the 10% highest seed‐yielding genotypes from a second‐cycle family selection trial: 16.0% of progeny were identified with a high seed‐yielding father. However, progeny plants with two high seed‐yielding parents did not produce more seeds than traditionally selected progeny (27.3 g vs. 30.7 g/plant, respectively). The 10% highest seed‐yielding genotypes displayed on average 2% self‐fertilization. Four genotypes were self‐fertile with individual selfing rates up to 20%. Our results discourage the use of marker‐assisted parentage analysis to improve seed yield in tetraploid red clover when the material has been preselected for seed yield. Breeders should be aware that intensive selection for seed yield in tetraploid red clover may inadvertently lead to selection for increased self‐fertility, which may increase inbreeding in the long term.  相似文献   

15.
Eucommia ulmoides Oliv. is strictly a dioecious perennial tree native to China. The pistillate plants are economically more useful than the staminate plants. The random amplified polymorphic DNA (RAPD) technique was used to screen markers of sex determination in this species. A 569 bp RAPD marker, marker linked to sex determination in E. ulmoides (MSDE), was found in all the pistillate but not in the staminate plants; its exclusiveness to pistillate plants was confirmed by Southern blotting. MSDE was sequenced and specific primers were synthesized to generate a 569bp pistillate-specific SCAR marker, SCARmr. SCARmr could be useful for screening E. ulmoides plants for gender even before they reach reproductive maturity, resulting in considerable saving of time and economic resources.  相似文献   

16.
Asparagus (Asparagus officinalis L.) is a dioecious species, with both male and female individuals. Male plants are more desirable to cultivate than female plants because they have higher yields, and, unlike female plants, they do not have a weed problem resulting from fallen seeds. A male-specific DNA marker is currently available to identify the sex of asparagus individuals using total DNA extracted from cladodes and roots. However, no published method is currently available for DNA extraction and PCR amplification from asparagus seeds. In this study, we tested several heat-resistant DNA polymerases for PCR and several methods for extracting DNA from asparagus seeds and successfully established a method for identifying the sex of asparagus seeds using this male-specific DNA marker. We found that PCR amplification of DNA extracted from asparagus seeds using simple methods such as single-step DNA extraction requires the use of high efficiency DNA polymerase. By contrast, many types of heat-resistant DNA polymerases can be used for PCR amplification of high-quality DNA extracted from asparagus seeds using a commercially available DNA extraction kit. Our method for sex identification of asparagus seeds could facilitate quality checking of all-male asparagus seeds and accelerate the screening of super-male asparagus.  相似文献   

17.
A recombinant inbred line (RIL) mapping population (F8) was generated by crossing Vigna mungo (cv. TU 94‐2) with Vigna mungo var. silvestris and screened for mungbean yellow mosaic virus (MYMV) resistance. The inter simple sequence repeat (ISSR) marker technique was employed to identify markers linked to the MYMV resistance gene. Of the 100 primers screened, 54 showed amplification of which 36 exhibited polymorphism between the parents TU 94‐2 (resistant) and V. mungo var. silvestris (susceptible). Individual plants from 53 RIL populations were analysed and one marker (ISSR8111357) was identified as tightly linked to the MYMV resistant gene at 6.8 cM. Both the phenotype as well as the ISSR8111357 marker segregated in a 1 : 1 ratio. The ISSR8111357 marker was sequenced and sequence characterized amplified region (SCAR) primers were designed (YMV1‐F and YMV1‐R) to amplify the marker. Screening for the SCAR marker in the RIL population distinguished the MYMV resistant and susceptible plants, agreeing well with the phenotypic data. The ISSR8111357 marker was validated using diverse blackgram genotypes differing in their MYMV reaction. The marker will be useful for the development of MYMV‐resistant genotypes in blackgram.  相似文献   

18.
Lagerstroemia (crape myrtle) are famous ornamental plants with large pyramidal racemes, long flower duration and diverse colours. Genetic maps provide an important genomic resource of basic and applied significance. A genetic linkage map was developed by genotyping 192 F1 progeny from a cross between L. caudata (female) and L. indica (‘Xiang Xue Yun’) (male) with a combination of amplification fragment length polymorphisms (AFLP) and simple sequence repeats (SSR) markers in a double pseudo‐testcross mapping strategy. A total of 330 polymorphic loci consisting of 284 AFLPs and 46 SSRs showing Mendelian segregation were generated from 383 AFLP primer combinations and 150 SSR primers. The data were analysed using JoinMap 4.0 (evaluation version) to construct the linkage map. The map consisted of 20 linkage groups of 173 loci (160 AFLPs and 13 SSRs) covering 1162.1 cM with a mean distance of 10.69 cM between adjacent markers. The 20 linkage groups contained 2–49 loci and ranged in length from 7.38 to 163.57 cM. This map will serve as a framework for mapping QTLs and provide reference information for future molecular breeding work.  相似文献   

19.
Yellow mosaic disease (YMD) caused by mungbean yellow mosaic virus (MYMV) is the most important disease of mungbean, causing great yield loss. The present investigation was carried out to study the inheritance and identify molecular markers linked with MYMV resistance gene by using F1, F2 and 167 F2 : 8 recombinant inbred lines (RILs) developed from the cross ‘TM‐99‐37’ (resistant) × Mulmarada (susceptible). The F1 was susceptible, F2 segregated in 3S:1R phenotypic ratio and RILs segregated in 1S:1R ratio in the field screening indicating that the MYMV resistance gene is governed by a single recessive gene. Of the 140 RAPD primers, 45 primers showing polymorphism in parents were screened using bulked segregant analysis. Three primers amplified specific polymorphic fragments viz. OPB‐07600, OPC‐061750 and OPB‐12820. The marker OPB‐07600 was more closely linked (6.8 cM) with a MYMV resistance gene as compared to OPC‐061750 (22.8 cM) and OPB‐12820 (25.2 cM). The resistance‐specific fragment OPB‐07600 was cloned, sequenced and converted into a sequence‐characterized amplified region (SCAR) marker and validated in twenty genotypes with different genetic backgrounds.  相似文献   

20.
Waxy (Wx) protein is a key enzyme for synthesis of amylose in endosperm. Amylose content in wheat grain influences the quality of end‐use products. Seven alleles have been described at the Wx‐D1 locus, but only two of them (Wx‐D1b, Wx‐D1e) were genotyped with codominant markers. The waxy wheat line K107Wx1 developed by treating ‘Kanto 107’ seeds with ethyl methanesulphonate carries the Wx‐D1d allele. However, no molecular basis supports this nomenclature. In the present study, DNA sequence analysis confirmed that a single nucleotide polymorphism in the sixth exon of Wx‐D1 changed tryptophan at position 301 into a termination codon. Based on this sequence variation, a PCR‐based KASP marker was developed to detect this point mutation using 68 BC8F1 plants and 297 BC8F2 lines derived from the cross ‘Ningmai 14’*9/K107Wx1. Combined with codominant markers for the Wx‐A1 and Wx‐B1 alleles, waxy and non‐waxy near‐isogenic lines were distinguished. The KASP marker was efficient in identifying the mutant allele and can be used to transfer waxiness to elite lines.  相似文献   

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