Oil Crop Breeding Research Articles

Morphological and reproductive characterization of nascent allotetraploids cross-compatible with cultivated peanut (Arachis hypogaea L.)

Peanut improvement is limited by a narrow genetic base. However, this obstacle can be circumvented by incorporating phenotypic variability from wild, diploid Arachis species through interspecific hybridizations. In this study, four allotetraploid interspecific hybrids IpaCor4x (A. ipaensis × A. correntina), IpaDur4x (A. ipaensis × A. duranensis), IpaSten4x (A. ipaensis × A. stenosperma), and ValSten4x (A. valida × A. stenosperma) were created and morphologically characterized through the following parameters: flower count, flower size, flower banner pigmentation, leaf area and weight, leaf hairiness, main stem height, internode length, percent of reproductive nodes, biomass, 100 pod weight, and 100 seed weight. For every trait, except for flower banner absorption at 380 nm, at least one or more allotetraploids differed from the cultivated peanut control. In general, these allotetraploids had a greater production of flowers during the growing season, larger flowers, larger and hairier leaves, taller main stems, longer primary laterals, longer internodes, lower percentage of reproductive nodes, heavier plant body masses, and smaller seeds and pods. This phenotypic diversity can be utilized directly in ornamental and forage breeding, while for oil and food crop breeding, this diversity will likely need to be selected against while desirable traits such as disease and insect resistance and abiotic stress tolerances derived from the wild diploid species are maintained.

AtMIF1 increases seed oil content by attenuating GL2 inhibition.

Vegetable oil is a major edible oil and an important industrial raw material. However, breeders have found it challenging to improve the oil content of crop seeds, and little is known about regulators with the potential to increase oil content via molecular engineering in modern oil crop breeding. We reported an F-box protein, Arabidopsis thaliana MYB Interaction Factor 1 (AtMIF1), which is a member of the ubiquitin-protein ligase E3 complex involved in the 26S proteasome protein degradation pathway. AtMIF1 physically interacts with MYB domain protein 5 (MYB5), which results in MYB5 degradation, so that transcriptional activation of the MYB/bHLH/WD-repeat (MBW) complex does not occur normally and GLABRA2 (GL2), encoding an inhibitor of oil content and functioning as a direct downstream gene of MBW, is not properly transcribed. AtMIF1 functioned as a positive regulator that increases oil content by attenuating GL2 inhibition. We overexpressed AtMIF1 and obtained transgenic plants with significantly higher seed oil contents. Importantly, both vegetative and reproductive growth of the transgenic plants appeared normal. In summary, this work reveals a novel regulator, AtMIF1, and a new regulatory pathway, 26S proteasome-AtMIF1-MYB5, for increasing the oil content of seeds without affecting plant growth, thus facilitating oil crop breeding.

Genetic and Phenotypic Diversity of the Sunflower Collection of the Pustovoit All-Russia Research Institute of Oil Crops (VNIIMK)

Abstract Publicly supported collections of cultivated germplasm are one of the key sources of new genes for crop improvement. VNIIMK is the leading organization in oil and essential oil crop breeding and seed growing in the Russian Federation with more than a century-long history. Sunflower varieties created by V.S. Pustovoit at VNIIMK became the basis for the development of the modern sunflower varieties worldwide. In the present study, 186 sunflower lines from the VNIIMK collection were characterized based on their genotype and general morphological and phenological economically-important traits. Additionally, for 99 sunflower lines fatty acid content, seed oil content, seed husk content, 100-seed weight, and seed number in the head were determined. Sequencing of RAD-libraries and the subsequent analysis have identified 65,553 variants including SNPs and indels. LD analysis revealed substantial variability across the genome. The longest LD blocks (>5,000 Kb) were found in the linkage groups 1, 5, and 17. The analysis revealed significant genetic and phenotypic diversity of the VNIIMK sunflower collection. Novel significant associations with linolenic acid content in the seeds were found on LGs 8, 9, and 17.

BnLATE, a Cys2/His2-Type Zinc-Finger Protein, Enhances Silique Shattering Resistance by Negatively Regulating Lignin Accumulation in the Silique Walls of Brassica napus.

Silique shattering resistance is one of the most important agricultural traits in oil crop breeding. Seed shedding from siliques prior to and during harvest causes devastating losses in oilseed yield. Lignin biosynthesis in the silique walls is thought to affect silique-shattering resistance in oil crops. Here, we identified and characterized B. napus LATE FLOWERING (BnLATE), which encodes a Cys2/His2-type zinc-finger protein. Heterologous expression of BnLATE under the double enhanced CaMV 35S promoter (D35S) in wild-type Arabidopsis plants resulted in a marked decrease in lignification in the replum, valve layer (carpel) and dehiscence zone. pBnLATE::GUS activity was strong in the yellowing silique walls of transgenic lines. Furthermore, the expression pattern of BnLATE and the lignin content gradient in the silique walls at 48 days after pollination (DAP) of 73290, a B. napus silique shattering-resistant line, are similar to those in transgenic Arabidopsis lines expressing BnLATE. Transcriptome sequencing of the silique walls revealed that genes encoding peroxidases, which polymerize monolignols and lignin in the phenylpropanoid pathway, were down-regulated at least two-fold change in the D35S::BnLATE transgenic lines. pBnLATE::BnLATE transgenic lines were further used to identify the function of BnLATE, and the results showed that lignification in the carpel and dehiscence zone of yellowing silique also remarkably decreased compared with the wild-type control, the silique shattering-resistance and expression pattern of peroxidase genes are very similar to results with D35S::BnLATE. These results suggest that BnLATE is a negative regulator of lignin biosynthesis in the yellowing silique walls, and promotes silique-shattering resistance in B. napus through restraining the polymerization of monolignols and lignin.

The BnGRF2 gene (GRF2-like gene from Brassica napus) enhances seed oil production through regulating cell number and plant photosynthesis

Seed yield and oil content are two important agricultural characteristics in oil crop breeding, and a lot of functional gene research is being concentrated on increasing these factors. In this study, by differential gene expression analyses between rapeseed lines (zy036 and 51070) which exhibit different levels of seed oil production, BnGRF2 (Brassica napus growth-regulating factor 2-like gene) was identified in the high oil-producing line zy036. To elucidate the possible roles of BnGRF2 in seed oil production, the cDNA sequences of the rapeseed GRF2 gene were isolated. The Blastn result showed that rapeseed contained BnGRF2a/2b which were located in the A genome (A1 and A3) and C genome (C1 and C6), respectively, and the dominantly expressed gene BnGRF2a was chosen for transgenic research. Analysis of 35S-BnGRF2a transgenic Arabidopsis showed that overexpressed BnGRF2a resulted in an increase in seed oil production of >50%. Moreover, BnGRF2a also induced a >20% enlargement in extended leaves and >40% improvement in photosynthetic efficiency because of an increase in the chlorophyll content. Furthermore, transcriptome analyses indicated that some genes associated with cell proliferation, photosynthesis, and oil synthesis were up-regulated, which revealed that cell number and plant photosynthesis contributed to the increased seed weight and oil content. Because of less efficient self-fertilization induced by the longer pistil in the 35S-BnGRF2a transgenic line, Napin-BnGRF2a transgenic lines were further used to identify the function of BnGRF2, and the results showed that seed oil production also could increase >40% compared with the wild-type control. The results suggest that improvement to economically important characteristics in oil crops may be achieved by manipulation of the GRF2 expression level.

Plasmopara halstedii

<i>Plasmopara halstedii</i>

In vitro pollen culture and the regeneration of Brassica campestris L. plants

Brassica campestris (Brassica rapa L. ssp. oleifera) is an important oilseed crop, particularly in Finland. Pollen culture techniques for haploid production have been developed, but B. campestris is relatively recalcitrant in pollen culture. Twenty eight genotypes of B. campestris were included in this study. The donor plants were grown in the greenhouse and transferred to the growth cabinet before bolting. Buds (2-4 mm long) were selected, macerated in B 5 medium, then NLN liquid culture medium was added. The microspores were incubated in the dark at 32°C for 72 h, then at 25°C for a further three weeks. Nineteen genotypes produced microspore-derived embryos. The highest yield was more than 300 embryos per 100 buds. Activated charcoal (150 mg/L) promoted embryogenesis, pollen development was faster and the embryo yield was higher. Plants were regenerated after transferring embryos to a solid B 5 medium. Colchicine solution was used to double the chromosome complements. About 100 regenerate plants have been obtained in our laboratory, and these haploids will be useful for the oilcrop breeding.

Improvements of the Fat Quality by the Oil Crop Breeding

Improvements of the Fat Quality by the Oil Crop Breeding

Some Experiences of Using Different Analytical Methods in Screening for Oil and Protein Content in Rapeseed

AbstractIn this study some analytical methods, which have been used in oil crop breeding, are compared from the point of view of plant breeding. For oil content determination a gravimetric method, NMR and NIR have been used. Protein content has been determined by the classical Kjeldahl technique, by the Biuret method and by NIR. The results indicate that the NIR spectroscopy is specially useful in screening breeding materials. This method enables the breeder to select for several quality characters simultaneously at a high speed and at a low cost. Since NIR spectroscopy is nondestructive, the same seed lot can be used for analysis and planting. Thus it is possible to select on a large scale for single plants.