Relationships between seed oil content and fatty acid composition in high stearic acid sunflower

The high stearic acid sunflower mutant CAS-3 is characterized by a low seed oil content, which might represent a constraint for the commercial production of high stearic acid sunflower oil. The objective of the present research was to investigate the relationships between fatty acid profile and seed oil content in CAS-3. Plants of CAS-3 were reciprocally crossed with plants of breeding line ADV-37, with high oil content and standard fatty acid profile. Oil content and fatty acid composition were measured in individual F₂ seeds and F₂ plants (F₃ seeds averaged). Both F₂ seeds and F₂ plants from the cross ADV-37 × CAS-3 had a significantly higher oil content than those from the reciprocal cross, which indicated the existence of cytoplasmic effects in the genetic control of the trait. A consistent negative correlation between oil content and palmitic acid and a positive correlation between oil content and oleic acid were detected both in F₂ seeds and F₂ plants. Conversely, no consistent correlation between oil content and stearic acid was observed, which suggested the feasibility of simultaneous selection for both traits.     

Cytogenetic analysis of F1, F2 and BC1 plants from intergeneric sexual hybridization between Sinapis alba and Brassica oleracea by genomic in situ hybridization

By intergeneric sexual hybridization between Sinapis alba and Brassica oleracea , F₁, F₂ and BC₁ progeny plants were produced. S. alba plants (genome SS, 2n = 24) were pollinated with B. oleracea (genome CC, 2n = 18), and the fertile F₁ plants were pollinated with B. oleracea to obtain BC₁ plants. GISH analysis showed that 10 out of 12 F₁ plants had 12 S. alba chromosomes (one full S chromosome set) and nine B. oleracea chromosomes (one C chromosome sets), representing the expected hybrids. However, two F₁ plants had 12 S chromosomes and 18 C chromosomes (two C chromosome sets), indicating unexpected hybrids. A maximum of three trivalents between C and S chromosomes were identified at metaphase I of semi-fertile F₁ pollen mother cells (PMCs), which indicates homology and chromosome pairing between these two genomes. The C genome had obviously been doubled in two F₂ plants from selfed semi-fertile F₁ plants. BC₁ plants consisted of 18 C chromosomes and different numbers of one, five and six additional S chromosomes, respectively. Monosomic alien addition lines developed in the present study can be used for B. oleracea breeding and Sinapis alba gene mapping.     

Development and agronomic performance of common bean lines simultaneously resistant to anthracnose, angular leaf spot and rust

The common bean is affected by several pathogens that can cause severe yield losses. Here we report the introgression of resistance genes to anthracnose, angular leaf spot and rust in the 'carioca-type' bean cultivar 'Rudá'. Initially, four backcross (BC) lines were obtained using 'TO', 'AB 136', 'Ouro Negro' and 'AND 277' as donor parents. Molecular fingerprinting was used to select the lines genetically closer to the recurrent parent. The relative genetic distances between 'Rudá' and the BC lines varied between 0.0% and 1.99%. The BC lines were intercrossed and molecular markers linked to the resistance genes were used to identify the plants containing the genes of interest. These plants were selfed to obtain the F₂, F₃ and F₄ plants which were selected based on the presence of the molecular markers mentioned and resistance was confirmed in the F₄ generation by inoculation. Four F_4:7 pyramid lines with all the resistance genes showed resistance spectra equivalent to those of their respective donor parents. Yield tests showed that these lines are as productive as the best 'carioca-type' cultivars.     

Production of intergeneric hybrids between Raphanm and Moricandia

Intergeneric F₁ hybrids between Raphanus sativus (2n = 18, RR) and Moricandia arvensis (2n = 28, MaMa) have been produced through ovary culture followed by embryo culture, when M. arvensis was used as a pistillate parent. Six BC₁ plants were also obtained through ovary culture followed by embryo culture in the backcross of an amphidiploid F₁, hybrid with R. sativus cv. 'Pink ball'. Two BC₁ plants were ses-quidiploids (2n = 32, MaRR), and the other BC₁, plants were hyperploid with 2n = 55, having MaMaRRR genomes. BC₂, seeds were obtained by conventional pollination in the successive backcross of two sesquidiploid BC₁, plants with R. sativus cv. 'Pink ball'. Their seed set percentages were 12.7% and 17.0%, respectively. These novel hybrid plants and derived progenies may be valuable materials for the genetic investigation and breeding of Brassiceae , including R. sativus.     

Hybridization of Thinopyrum distichum and Secale cereale

An attempt was made to determine whether the salt tolerance genes of Thinopyrum distichum would be expressed in the presence of the rye genomes and if it would be possible to improve and utilize its hybrid with rye as a salt-tolerant fodder crop. Th. distichum florets were pollinated with diploid and tetraploid rye but hybrids were obtained only with tetraploid rye. The F₁ had 28 chromosomes and expressed high levels of salt tolerance. Fertility could not be induced through colchicines treatment but the plants produced some apomictic seeds during the summer months. The F₂ had 20-22 chromosomes and retained two complete or near-complete rye genomes. The F₂ plants responded better to colchicine treatment, however, the doubled hybrids remained male sterile. In summer, one F2 plant produced many apomictic seeds with chromosome numbers ranging from 14 to 16 (primarily rye chromosomes). The mechanism that caused the preferential loss of Thinopyrum chromosomes in each apomictic cycle remains unknown. The F₃ phenotypically resembled rye, had primarily reductional male meioses and produced seemingly functional pollen, but were self-sterile.     

Molecular mapping of a new red mutant gene (Rs) in upland cotton

In recent years, there has been slow progress in improving cotton yield. It is known that the F₁ generation from the cross of the new red mutant and the normal green leaf plant has high photosynthetic efficiency. Therefore, cloning the new red mutant gene and further introducing it into other crops through transgenic techniques is a promising approach for achieving high photosynthetic efficiency through breeding. To map this new mutant gene, tentatively named R _s , the authors constructed an F₂ generation containing 1214 individual plants from mutant EH083 ( Gossypium hirsutum ) and Hai 7124 ( Gossypium barbadense ). Fifty-five pairs of simple sequence repeats and sequence-related amplified polymorphism (SRAP) primers on chromosome 7 were selected to screen the two parents. Finally, the R _s gene was mapped at the 0.3 cM interval flanked by markers NAU3735 and NAU1048.     

Relationship of Root and Shoot Characters in Parent, F1 and F2 Populations of Rice

The direct and indirect contributions of root characters — root length, roots/plant, fresh and dry root weight on grain yield/plant were worked out from a 7 × 7 diallel set of rice hybrids. The materials were grown in pots with four replications. Path analysis was done at genotypic level of correlation.
The grain yield/plant showed positive correlation with all the root characters in parent, F₁ and F₂ except with roots/plant in F₁ population. Fresh root weight demonstrated positive direct effect on grain yield/plant in all the three generations. Roots/plant had highly positive direct effect in F₂. Direct effects were negative in respect of root length and dry root weight in F₂ generation.     

不同生根粉浓度对5种木本植物插穗萌发和生根的影响

蒙古莸、金叶莸、沙棘、沙枣和红雪果是近年来北京地区园林绿化中新引进的5种观赏性优良、环境适应性广的木本植物。为了扩大其种植,采用扦插法进行繁殖研究,研究了不同浓度生根粉处理对其扦插苗萌发率和生根率的影响。结果表明,一定浓度的生根粉处理能提高蒙古莸、金叶莸和沙棘的萌发率,也能提高沙棘、沙枣、红雪果的生根率和蒙古莸、金叶莸、沙棘、红雪果的生根数。中、低浓度的生根粉处理能够显著促进5种木本植物插穗的根长。生根粉也能提高沙枣的插穗上盆成活率。综上所述,用0.15~0.5 g/L的生根粉处理能够显著促进这些木本植物的萌发、生根、根长或扦插成活率,从而促进这些木本植物的扦插繁殖。     

Identification of AFLP and RAPD markers linked to anthracnose resistance in grapes and their conversion to SCAR markers

Resistance to anthracnose or black spot ( Elsinoe ampelina ), a serious fungal pathogen in viticulture and table grape production, was investigated on 25 grape cultivars. Bioassays performed with culture filtrates produced by the pathogen revealed 14 resistant genotypes. In most plants resistance originated from Vitis labrucsa but also genotypes with V. rupestris and V. riparia  ×  V. rupestris background showed resistance. Genetic analysis was conducted in F₁, S₁ and BC₁ plants developed from various cultivars. In total, 326 F₁ plants were evaluated, 172 genotypes proofed to be resistant, whereas 154 were susceptible to anthracnose. A Mendelian segregation ratio of 1 : 1 (χ² = 0.30–0.65) indicating that anthracnose resistance is controlled by a single dominant gene. To facilitate the use of marker-assisted selection in grape-breeding PCR-based markers were developed by random amplified polymorphic DNA and amplified fragment length polymorphism in bulk segregant analysis. Finally, OPB 15₁₂₄₇ was developed as a sequence characterized amplified region marker being diagnostic for the locus of resistance to anthracnose in all resistant genotypes tested. Within the 25 grape cultivars OPB 15₁₂₄₇ is diagnostic in the genetic background of both V. labrucsa and V. rupestris and V. riparia  ×  V. rupestris .     

Inheritance of very high glucosinolate content in Ethiopian mustard seeds

Seed meal amendments rich in glucosinolates are of interest for soil pest and disease control. The Ethiopian mustard ( Brassica carinata A. Braun) line N2-6215, with very high levels of seed glucosinolates (160 μmol/g), was developed from the line C-101 (116 μmol / g) following mutagenesis. The objective of this research was to study the inheritance of very high seed glucosinolate content. Plants of N2-6215 were reciprocally crossed with plants of the line C-101. The F₁, F₂, and BC₁F₁ plant generations were evaluated in two environments and seeds from individual plants were analysed for total glucosinolate content. The very high glucosinolate content in N2-6215 seeds was largely subject to maternal control. No cytoplasmic effects were detected. The trait was found to be oligogenic and determined by at least two or three genes. The estimates of broad-sense heritability were 0.45 and 0.58 in both environments, whereas the estimates of narrow-sense heritability were 0.35 and 0.50. The moderate heritability and oligogenic control of the trait suggest the feasibility of breeding for increased seed glucosinolate content in Ethiopian mustard.     

沙生柽柳扦插苗生根条件优化研究

针对流沙固定先锋树种沙生柽柳扦插苗不易生根的问题,进行了沙生柽柳扦插基质、插穗长度、插穗木质化程度及外源激素处理等关键因素筛选试验,探讨沙生柽柳扦插繁殖优化条件。结果表明：沙生柽柳扦插繁殖能力普遍较低,插穗成活率在6.67%~31.11%之间;插穗选用15cm长的1年生硬枝为宜,1年生硬枝扦插成活率高达31.11%,15cm插穗成活率为10.37%;扦插基质以保湿性能较好的壤土为宜,插穗成活率9.63%;外源激素诱导以200mg/L的IBA浸泡20min效果最佳,不同激素类型诱导中,IBA处理效果最好,插穗最高成活率达14.07%,为CK对照处理的6~7倍;不同激素浓度诱导中,200mg/L低浓度IBA处理插穗成活率高达22.22%;不同激素处理时间诱导中,经20min浸泡的IBA激素处理的插穗成活率24.44%。     

外源激素与基质对黄果厚壳桂扦插生根的影响

为提高黄果厚壳桂扦插生根率和苗木成活率,探讨该树种的扦插生根特性,分析外源激素和基质对扦插的影响,以期为黄果厚壳桂的苗木繁育和树种扩繁提供科学参考。以黄果厚壳桂为研究对象,采用L₉(3⁴)正交设计开展扦插试验,通过方差分析、相关分析和主成分分析3种方法阐明外源激素和基质对该树种扦插生根的影响。结果表明,使用黄心土做扦插基质,黄果厚壳桂的扦插生根率最高,达70.0%,显著大于河沙与泥炭土+椰糠。在不同外源激素处理中,IAA处理的枝条扦插生根率和抽梢率最高,分别为66.7%和52.2%。激素浓度为250 mg/L时,扦插生根率最高,并随激素浓度升高而降低,但基部愈伤率效果相反。不同浸泡时间处理对黄果厚壳桂的扦插生根率和基部愈伤率的影响不同,其中30 min处理的生根率最高,而10 min处理的基部愈伤率最高。综合3种统计分析方法的研究结果,以黄心土为扦插基质,使用浓度为250 mg/L的IBA生根液浸泡插穗基部10 min,黄果厚壳桂扦插生根和抽梢效果最好,生根率和抽梢率分别是76.7%和70.0%。     

Evaluation of the Heterosis on Leaf Photosynthesis of Remote-Cross F1 Rice (Oryza saliva L.)

The heterosis of leaf photosynthesis was studied on the main characters included in the range from CO₂exchange rate (CER) to enzymatic activity using a remote cross F, rice. The CER was significantly higher than those of the parental strains, showing a 111 % heterosis effect on average; at the same time strong heterosis was observed for the leaf area production and growth. Also stomatal and mesophyll conductances increased in the F₁ rice, which may contribute to the increase in CER. Chlorophyll content (Ch1), soluble protein content (SPC) and ribulose 1,5-bisphosphate (RuBP) carboxylase activity (RCA) were measured as the internal factors related to photosynthesis, and compared between the F₁, rice and the parents. For all these factors, the F₁ rice showed low values compared to the parents. Positive heterosis was not expressed here. On the other hand, the specific activity of RCA (RCA/SPC) increased in the F₁, rice, showing a 120% heterosis effect. This may be regarded as one of the main causes for the increase in CER of the F₁, rice. High CER expressed as heterosis concurrently with large leaf area production is one of the important findings in our study, and this may suggest a high possibility of further improvement in biomass production or yield of rice by gathering the advantageous elements into a hybrid plant.     

Diallel analysis of sugar composition of 10 vegetable soybean lines

Few studies have evaluated vegetable soybean for sugar content at the green pod stage. Information on combining ability and type of gene action that governs inheritance of seed traits can help breeders to select suitable parents and devise an appropriate breeding strategy. Ten vegetable soybean accessions were crossed in a complete diallel mating design. Parent lines and F₂ and F₃ progenies were evaluated for two nutritional components. In this study, both general and specific combining ability and reciprocal effects were significant for sucrose and total sugar. Cultivars 'Kanrich', 'Pella', 'Verde' and V81-1603 had good general combining ability for high sucrose. In general, high sucrose content was observed in progeny of the early maturity group genotypes 'Kanrich', 'Pella' and 'Verde'. The best combiners for high total sugar content were 'Verde', V81-1603 and PI 399055. These genotypes could serve as genetic sources in a vegetable soybean breeding programme.     

Production and characterization of an amphidiploid line between Brassica rapa and a wild relative Diplotaxis tenuifolia

Intergeneric hybridization was performed between Brassica rapa and Diplotaxis tenuifolia following embryo rescue. Twenty-three F₁ hybrid plants were developed from the cross B. rapa  ×  D. tenuifolia and confirmed to be amphihaploids with 21 chromosomes in mitosis. Chromosome doubling of F₁ hybrids by colchicine treatment resulted into five amphidiploid plants which exhibited (20–21)_II + (0–2)_I at metaphase I (MI) of pollen mother cells. Sib-crossing and/or open-pollination among amphidiploid plants for more than four generations resulted in the development of an ADt-06 line with reproductive systems capable of maintaining an amphidiploid line. The ADt-06 line was intermediate in some morphological traits between two parental species, and was characterized by a slightly pungent taste as a physiological trait. Analyses for genomic DNA confirmed that this line was a hybrid between two species. This new amphidiploid ADt-06 line could be a useful genetic resource for the breeding of new leafy salad vegetables.     

Inheritance of time of flowering in upland cotton under natural conditions

Time to flowering is an essential component of the adaptation and productivity of cotton ( Gossipium hirsutum ) in various agro-ecological zones. This article presents a study of the genetic control of this trait in two crosses obtained from different early-maturity parental lines. In each cross, multiple generations including P₁, F₁, P₂, B₁, B₂ and F₂ were evaluated under two natural field conditions in 2004 and 2005. The data on time to flowering in the F₂ populations had a continuous distribution but deviated from normality. A joint segregation analysis (JSA) revealed that time of flowering in upland cotton was controlled by a mixture of an additive major gene and additive-dominant polygenes. The first- and second-order genetic parameters were all calculated based on the mixture of major gene and polygene inheritance models using JSA. These results suggested that there was considerable genetic diversity and complexity in days to anthesis in upland cotton. This variation can be used to formulate the most efficient breeding strategy and to design cotton for a particular environment.     

ABT处理和插穗长度对栝楼扦插苗质量的影响

栝楼是雌雄异株植物,在人工栽培过程中,扦插快繁技术能有效控制雌雄株合适比例;本试验研究了ABT不同浓度（0mg/l、50 mg/l、100 mg/l和200 mg/l）、100 mg/l浓度时不同浸泡时间（10min、20 min、40 min和60 min）和不同插穗长度（1节、2节和3节）对扦插生根率和移栽成活率的影响。实验结果表明：在用珍珠岩做基质时,栝楼扦插快繁适合的条件是：选用当年生的2节插穗,用100mg/l浓度的ABT粉浸泡40分钟;该处理条件下,插穗具有100%的生根率和99%的移栽成活率以及较好的综合经济效益     

Pea weevil, Bruchus pisorum L. (Coleoptera: Bruchidae), resistance in Pisum sativum×Pisum fulvum interspecific crosses

The pea weevil, Bruchus pisorum (L.), is one of the most intractable pest problems of cultivated pea, Pisum sativum L., in the world. This study investigated the transfer of pea weevil resistance from two accessions (PI 595946, PI 343955) of wild pea, Pisum fulvum Sibth. & Sm., to interspecific populations derived from crossing these accessions with a weevil-susceptible pea cultivar ('Alaska 81'). Partial life tables characterized weevil stage-specific mortality and survivorship on parents and interspecific progeny in two glasshouse trials. Larval mortality rates on pods (F₃ plants) of several F_2:3 families were between 36.0% and 52.9%. These means were statistically similar to mean mortality rates on pods of resistant parents (45.4% and 46.2%), but significantly greater than mean rates on the susceptible parent (1.2% and 10.6%). Pod surface characteristics contributed to high neonate larval mortality on pods of resistant parents and interspecific progeny. Seed resistance was not broadly transferred to interspecific progeny [revealed by high weevil survivorship in seeds (means mostly >80%) and high seed damage ratings of 3–5 where ratings of 1–2 denote resistance (production of resistant seed averaged 4.2% to 22.8%)]. Estimates of total weevil mortality on pods and seeds of eight F_2:3 families were 50–70%. Thus, weevil resistance in the Pisum secondary gene pool can be transferred to interspecific progeny, thereby providing a potential avenue to develop weevil-resistant pea cultivars.     

A codominant SCAR marker linked to the genic male sterility gene (ms1) in chili pepper (Capsicum annuum)

As one of the genic male sterility (GMS) materials in chili pepper ( Capsicum annuum L.), GMS1 has been used for commercial F₁ hybrid seed production. The male sterility of GMS1 is controlled by a recessive nuclear gene, named ms ₁ . In this study, we developed DNA markers linked to the ms ₁ locus using a combination of bulked segregant analysis and amplified fragment length polymorphism (AFLP) in a segregating sibling population. From the screening of 1024 AFLP primer combinations, the AFLP marker E-AGC/M-GTG (514 bp) was identified as being linked to the ms ₁ locus at a distance of about 3 cM. Based on internal sequencing analysis of the E-AGC/M-GTG marker between male fertile and sterile plants, we identified three small deletions with a size of altogether 42 bp in the male-fertile plant and developed a codominant sequence characterized amplified region (SCAR) marker. This SCAR marker may be valuable for marker-assisted breeding in the hybrid seed production system of chili pepper using the GMS1 line.     

短梗大参扦插繁殖技术研究

建立短梗大参扦插繁殖技术,为其苗木的规模化生产及推广应用提供技术支持。采用常规扦插方法,以短梗大参为试验材料,研究插穗类型、扦插基质、不同种类及浓度的生长调节剂对短梗大参扦插生根的影响。不同插穗类型对短梗大参扦插生根的影响显著(P＜0.05),3年生硬枝的生根效果明显优于1年生嫩枝。不同基质的生根效果差异显著(P＜0.05),其中黄心土和椰糠生根效果较好,河沙、谷壳灰次之,珍珠岩生根效果差。不同植物生长调节剂及浓度对短梗大参扦插生根有明显的影响(P＜0.05),其中以2000 mg/LIBA处理的插穗生根效果最佳,生根率达98.8%,平均根数为93.75,平均根长为4.23 cm,根系效果指数高达409.18,与对照相比,其生根数量和根系效果指数分别提高了3.54倍和4.35倍。不同生长调节剂混合使用不利于短梗大参的扦插生根。短梗大参合适的扦插条件为：扦插基质为黄心土,插穗为3年生硬枝,速蘸2000 mg/L IBA溶液处理。生产上不宜采用生长调节剂混合使用。