Summer Rape Research Articles

THE INFLUENCE OF MIXTURES OF GROWTH REGULATORS AND FUNGICIDES ON THE SPRING RAPE SEEDS YIELDS AND QUALITY

Our trial aims at investigating the impact performed by the mixture of a growing-regulator and fungicides upon summer rape productivity, the crop structure, and quality, to justify applying of agrochemicals in smaller doses thus eliminating environment pollution and winning labour-saving resource and financial applying per unit of sowing- fields, and per unit of the gained production. In 2001 – 2003, Research institute of Agriculture preparations during the trial were tested applying half doses (0,5 1 ha–1), creating the preparation mixtures: Moddus+ Folicur, Modus + Juventus; Cycocel + Folicur Cycocel + Juventus, through spraying them throughout plant florescence-bud formation (GS 50). Owing to the mixtures of preparations, the number of side branches increased, on average, for 1-2, the number of legumes on a plant – for 22-25, the number of seeds per legume for 2- 4, the mass o f 1000 seeds: from 3,7 to 4,2 g, at the same time the length of rape”s stem”s shorted down to 10-20 cm, and the branching height to 5-14 cm. The highest efficiency, however, was reached when applying the mixture of Cycocel and Juventus.On average, throughout all the three years, thanks to applying of growing-regulators and fungicides the summer oilseed rape harvesting essentially increased, if compared to the Control. The increase of harvest was 0,53-0,81 t ha –1 (γ0,05 0,24 t ha-1). During the trial-years the very best preparation mixture was nominated, and it was the Cycocel + Juventus, which, on average, provided the seed harvest 3,31 t ha –1, and the oil output 1409 kg ha –1. Other mixtures ensured a related seed output – 3,03-3,15 t ha –1, and the oil output 1270-1302 kg ha–1.

Modulating flowering time and prevention of pod shatter in oilseed rape

Floral induction is a key developmental switch in plants that leads to the production of flowers, fruits and seeds, which are of paramount importance for human life. To meet the demands of several crop harvests per year, or the growth of crop plants in regions with short vegetation times and for the production of ornamental plants, the timing of the floral transition is very important. The discovery of genes that are involved in flowering time control in model plants should allow the modulation of this developmental switch also in plants with economic value. By using a transgenic approach, we showed that a single MADS box gene accelerated flowering and seed ripening in summer rape plants. The MADSB transgene also partially substituted for the strict temperature requirements for flowering in winter rape plants. Transgenic winter rape plants expressing the MADSB transgene also produced more rigid siliques than wild type winter rape plants, and this prevented precocious seed dispersal.

Comparison of the effect of mur and nap cytoplasms on the performance of intercultivar summer rape hybrids

The performance of six isogenic pairs of male fertility restored, hand-crossed, summer rape (Brassica napus L.) hybrids, in the mur and nap cytoplasms, were investigated in four Manitoba environments. Hybrids in both cytoplasms exhibited high-parent heterosis for seed yield, total dry matter (TDM) and, to a lesser degree, harvest index (HI). Negative high parent heterosis for days to flowering, days to maturity, oil concentration and protein concentration was observed. Combined over hybrids within cytoplasms, the mur and nap cytoplasmic hybrid groups differed in oil concentration in all environments, and in protein concentration in one of four environments. Similarly, the mur hybrid group was lower-yielding and had lower TDM, HI and oil concentration, but higher protein concentration than the nap hybrid group. Even though there are some biological costs associated with the mur cytoplasm, especially for oil concentration, it appears that the mur cytoplasmic male sterility (CMS) system has good potential for use in summer rape hybrid cultivar breeding and commercial hybrid seed production, since hybrids in the mur cytoplasm display heterosis for many traits in absolute terms. Key words: Biological cost, Brassica napus L., cytoplasmic male sterility, heterosis, hybrid

Inheritance of maintenance and restoration of the Diplotaxis muralis (mur) cytoplasmic male sterility system in summer rape

The inheritance of Diplotaxis muralis (L) DC. mur cytoplasmic male sterile (CMS) system maintenance and restoration in summer rape (Brassica napus L.) was studied by crossing eight summer rape cultivars of diverse origin to a winter habit mur CMS A-line. The F1 progenies from all eight crosses were male fertile and were selfed to produce the F2 generation. The F2 generation was grown in the field and data on segregation for male fertility and sterility were recorded and analyzed. The F2 segregation data showed that mur CMS restoration in summer rape is controlled by dominant alleles at one to three restorer genes. The number of genes for the restoration of male fertility in mur CMS varied both among and, occasionally, within cultivars. Maintainer lines for mur CMS must carry recessive alleles in homozygous condition at all three restorer genes. The ready availability of summer rape restorers suggests that the mur CMS system has good potential for hybrid cultivar development and hybrid seed production in summer rape; however, maintainers in summer rape must first be discovered or developed. Key words: Cytoplasmic male sterility, canola, Brassica napus, male sterility

Development and evaluation of Diplotaxis muralis (mur) cytoplasmic male sterility system in summer rape

The Diplotaxis muralis male sterility inducing cytoplasm (mur cytoplasm) and its maintainer genes were transferred from the winter rapeseed male sterile line Mangun mur CMS A-line and the mur CMS maintainer line Mangun mur CMS B-line, respectively, into summer rape lines genetically related to the open-pollinated population cultivars Regent and Karat using standard cross, backcross and test cross breeding procedures. Three genetically identical summer rape mur CMS A-line and B-line pairs, Karat I A-line and B-line, Karat II A-line and B-line and Regent A-line and B line were developed. Flower morphology studies revealed that the mur CMS A-lines had anthers displaying a complete absence of pollen and floral morphology modifications similar to that seen for other CMS systems in summer rape. Seedling emergence, days to first flower, days to maturity, and height of the vernalized mur CMS Mangun A-line and B-line pair and the summer rape mur CMS A-line and B-line pairs were similar among treatments and equal for A-line and B-line pair comparisons within cultivars for plants grown in the greenhouse. There was no evidence of biological benefits or costs associated with the mur cytoplasm. The male sterility for the vernalized Mangun mur CMS A-line and the summer rape mur CMS A-lines was stable at temperatures up to 30/24EC. Key words: Brassica napus L., male sterility, temperature stability

Transgenic Brassica campestris Plants Expressing the gfp Gene

A protocol has been worked out for efficient regeneration and genetic transformation of summer rape (Brassica campestris L. var. oleifera). Cotyledons of the 5-day-old seedlings were transformed with Agrobacterium tumifaciens strain AGL cells comprising a binary vector with a selectable neomycin phosphotransferase II gene and a reporter gene encoding green fluorescent protein (GFP). Explants were cultured on a regeneration MS medium supplemented with ABA, and transformants were selected on the same medium (minus ABA and plus 70 mM AgNO3 and 15 mg/l kanamycin). The frequency of shoot regeneration on explant petioles was 30–40%. Transgenic plants were identified by GFP fluorescence and by polymerase chain reaction and Western blotting analysis. The transformation efficiency was as high as 75% of the total number of regenerated shoots.

The role of glucosinolates of Brassica genus in the crop system

Glucosinolates with Brassica genus as secondary metabolites have a lot of functions and effects. Glucosinolates form less than 2% of the overall sulphur content at the beginning of vegetation in different parts of the plants and during growth their content is decreasing and forms less than 0.1%. This low representation doubts their storage function. With its chemical composition, they are ranked among natural pesticides with active and passive resistance against diseases and pests. They show repellent effects and properties of natural biofumigators in soil after ploughing in their biomass as green fertilizing, or after ploughing in after harvest the leftovers of rape. The principle of these effects is decomposition products of glucosinolates – bioactive isothiocyanates. Very important from this point of view are turnip rape Rex and Brassica juncea, whose content of these compounds is the highest one and they are resistant against the attack of Ceutorrhynchus pleurostigma. The same effect showed also when attacked by Phoma lingam. With other winter Brassicas either hybrid or linea and summer rape is this defensive system suppressed because of their lowered content due to breeding interferences, leading to limitation of their anti-nutritional negative effects. It is possible to state the final result after finding out the production of the above matter, roots, and after evaluation of the sorbal characteristics of the soil and evaluation of the state of health of the following crop or vegetable. After this overall analysis, it will be possible to evaluate the biofumigation properties of accessible varieties of the Brassica genus.

Diplotaxis muralis (mur) cytoplasmic male sterility system maintainer occurrence and frequency in summer rape

No male sterile plants were found in the F1 progeny from crosses between a Diplotaxis muralis cytoplasmic male sterile (mur CMS) semi-winter habit rape (Brassica napus L.) A-line and 101 genetically diverse summer rape cultivars or strains. The frequency of occurrence of mur CMS system maintainer genotypes in summer rape is very low, possibly zero. Key words: Mur CMS system; Brassica napus L.

MillenniUM 03 summer rape

MillenniUM 03 summer rape (Brassica napus L.) is a high erucic acid, low glucosinolate (i.e., canola quality meal) cultivar. It has an average 26% yield advantage over Reston high erucic acid, low glucosinolate summer rape, is 25 g kg−1 higher in seed oil content than Reston, 21 g kg−1 higher in meal protein content than Reston, and is adapted to the southern B. napus growing regions of western Canada. Key words: Rape (summer), high erucic acid, low glucosinolate, cultivar description

MillenniUM 02 summer rape

MillenniUM 02 summer rape (Brassica napus L.) is a high erucic acid, low glucosinolate (i.e., canola-quality meal) cultivar. It has an average 27% yield advantage over Reston high erucic acid, low glucosinolate summer rape, is 18 g kg−1 higher in seed oil content than Reston, 20 g kg−1 higher in meal protein content than Reston, and is adapted to the southern B. napus growing regions of western Canada. Key words: Rape, erucic acid, glucosinolate, cultivar description

Evaluation of two self-incompatibility alleles in three summer rape (Brassica napus L.) cultivars by UV fluorescence microscopy, seed set and outcrossing rates

S-alleles W1 and T2 and an incompletely dominant white petal character were introgressed into the self-compatible (SC) summer rape (Brassica napus L. ssp. oleifera {Metzg.}) cultivars Global, Topas and Westar. The derived self-incompatible (SI) lines were evaluated for strength of incompatibility by ultraviolet fluorescence of pollen tubes, and by seed set. Pollen tube and seed set analyses showed the W1 and T2 alleles were strongly, moderately and weakly expressed in Topas, Global and Westar, respectively. Seed set data showed a significant difference between SI lines, but not between S-alleles, or between homozygous or heterozygous lines from the same SI cultivar. SI cultivar yellow petal (wild type) lines were field pollinated with SC white petal lines. Seed collected from the SI cultivars were evaluated for proportion of outcrossed progeny by recording the frequency of yellow petal and cream petal plants, which were the result of self- and cross-pollination, respectively. The proportion of outcrossed progeny (i.e., outcrossing rates) ranged from 23% to 79%. Topas SI lines had significantly higher outcrossing rates than Global SI lines, which corresponded to SI line seed set data. Environment, S-allele selection and genotype significantly affected outcrossing rates. Key words: Brassica napus, sporophytic incompatibility, S-allele, outcrossing rate

Q2 summer rape

Q2 is a canola quality summer rape cultivar adapted to areas where Brassica napus is grown in western Canada. Q2 combines high seed yield, good lodging resistance, and excellent resistance to blackleg disease. Key words: Rape (summer), cultivar description, yield, blackleg resistant, lodging resistant

MillenniUM 01 high erucic acid, low glucosinolate summer rape

MillenniUM 01 summer rape (Brassica napus L.) is a high-erucic acid, low-glucosinolate (i.e. canola-quality meal) cultivar. It has an average 7% yield advantage over Reston high erucic acid, low glucosinolate summer rape, is 11 g kg−1 higher in seed oil content than Reston, 25 g kg−1 higher in meal protein content than Reston, and is adapted to the southern B. napus growing regions of western Canada. Key words: Rape (summer), high erucic acid, low glucosinolate, cultivar description

A Comparison of the Strip and Blended Method of Seed Production for polCMS Summer Rape Hybrid Cultivars (Brassica napusL.)

Abstract Field seed production of hybrid summer rape (Brassica napusL.) at the University of Manitoba has been based on the cytoplas-mic male sterility system (CMS). Two methods of producing hybrid summer rape, the strip method and the blended method, were examined at two Manitoba locations. In the strip method, male (R-line) and female (A-line) parents were planted in separate rows utilizing a 1:1 row ratio. In the blended method, seed of the A-line and R-line parent are mixed in such a manner that the production field will consist of 90% A-line plants and 10% R-line plants. Seed yields ranged between 259 and 533 kg/ha from the strip method production fields, and between 646 and 1742 kg/ha in the blended method production fields. The percent hybridity ranged between 88 and 94% for seed lots from the strip method fields, and between 57 and 87% for the blended method fields. Since the seed lots obtained from the strip method fields were more consistent in their percent hybridity, it is recommended that the...

Sentry summer rape

Sentry is a summer rape (Brassica napus L.) cultivar with a high level of resistance to blackleg. Sentry is adapted to the long- and mid-season B. napus canola growing areas of western Canada. Key words: Rape (summer), blackleg resistance, cultivar description

Isogenic analysis of glufosinate-ammonium tolerant and susceptible summer rape lines

The development of transgenic Brassica napus L., tolerant to non-selective broad-spectrum herbicides, such as glyphosate and glufosinate-ammonium, could provide canola growers with an efficient method of weed control. The objective of this study was to determine whether the phosphinothricin-acetyl transferase (pat) gene which imparts tolerance to glufosinate-ammonium, affects the growth, development, productivity, and seed quality of B. napus canola. Nineteen glufosinate-ammonium tolerant and susceptible isogenic pairs of the B. napus cv. Westar, derived from independent transformation events, were evaluated in two field trials in each of 2 yr in Saskatchewan. Tolerant lines of six isogenic pairs were similar in their agronomic performance and seed quality to their susceptible counterparts indicating that glufosinate-ammonium tolerant B. napus can be developed that is not negatively affected in yield and quality by the presence of the pat gene. Several tolerant lines exhibited delayed flowering and maturity, lower biomass and seed yields, and lower oil and protein contents indicating positional effects of the pat gene on performance. Tolerant lines carrying two inserts of the pat gene were more negatively affected in their growth and development than single insert tolerant lines. The results of this study indicate that it would be beneficial to generate a number of different transformants and select elite transgenic lines which are not affected in their performance by the presence of the pat gene for use in cultivar development. Key words: Brassica napus, glufosinate-ammonium tolerance, isogenic analysis

Castor high erucic acid, low glucosinolate summer rape

Castor summer rape (Brassica napus L.) is a high-erucic acid rapeseed cultivar with canola-quality meal. Castor has an average 4% yield advantage over Mercury rapeseed and is 4 g kg−1 higher in seed oil than Mercury. Castor is adapted to the southern B. napus growing regions of western Canada. Key words: Rape (summer), high erucic acid-low glucosinolate, cultivar description

An investigation on linkage between white flower colour and erucic acid in summer rape

A dominant gene for white flower colour, derived from Brassica albogabra, is shown to be closely linked to a gene for seed erucic acid in summer rape (Brassica napus). This observation conflicts with a previous report on material of the same origin, where independent inheritance of these characters was reported. Key words: Brassica napus, flower colour, erucic acid, linkage, summer rape

Nectar quality in open-pollinated, pol CMS hybrid, and dominant SI hybrid oilseed summer rape

Nectar sugar composition and temporal patterns of nectar sugar production were examined in oilseed summer rape (Brassica napus L. ssp. oleifera (Metzg.)) from six open-pollinated, eight pol cytoplasmic male-sterile (CMS) hybrid and seven dominant self-incompatible (SI) hybrid cultivars at three field plot sites in Manitoba. The total sugar content of nectar samples was measured by the Dreywood anthrone reaction for total carbohydrate, and simple sugar composition was determined using an enzymatic bioanalysis for D-glucose, D-fructose and sucrose. Hybrid and open-pollinated cultivar flowers had similar sugar content. Mean total sugar content per flower also did not vary among hybrid breeding systems when compared within individual weeks of the bloom period or within daily sampling periods. However, for all cultivars, total nectar sugar content per flower was lower during the 08:00 and 11:00 h sampling periods and increased to maximum levels during the 14:00 and 16:00 h sampling periods. Significant differences in nectar sugar content were also found in relation to the bloom phenology of the cultivars. Cultivars produced the greatest amount of sugar per flower during the first 2 wk of the bloom period, then sugar production decreased in the third and fourth weeks. Nectar sugar ratios from all cultivars averaged approximately 1:1 glucose:fructose. Nectar glucose content among cultivars was similar but, among breeding systems, CMS cultivars tended to have lower amounts of glucose than SI or open-pollinated cultivars. Selecting for higher total sugar content may produce nectars more attractive to foraging honeybees (Apis mellifera L.), thereby ensuring adequate pollination of hybrid parental lines and F1 hybrid plants. Selecting for lower nectar glucose will produce honeys with more desirable granulation characteristics. Overall, the production and quality of nectar sugar in oilseed rape hybrids are similar to those of open-pollinated cultivars, and are not likely to adversely affect the pollinating activities of honeybees or their potential for honey production. Key words: oilseed summer rape, Brassica napus, honeybees, Apis mellifera, nectar, simple sugars

Venus high erucic acid, low glucosinolate summer rape

Venus summer rape (Brassica napus L.) is a high-erucic acid rapeseed cultivar with canola-quality meal. Venus has an average 5% yield advantage over Hero rapeseed with seed oil and protein contents comparable to Hero. Venus is adapted to the southern B. napus growing regions of western Canada. Key words: Rape (summer), high erucic acid-low glucosinolate, cultivar description