The chromosome number of the swede,Brassica napus L.

1938 ◽  
Vol 35 (3) ◽  
pp. 383-386 ◽  
Author(s):  
H. W. Howard
1984 ◽  
Vol 26 (6) ◽  
pp. 752-761 ◽  
Author(s):  
C. A. Newell ◽  
M. L. Rhoads ◽  
D. L. Bidney

Plants were regenerated from seedling tissue explants of four lines of winter rape (Brassica napus L.) including a cytoplasmic male sterile line carrying Raphanus sativus L. cytoplasm, and from leaf mesophyll protoplasts of the cytoplasmic male sterile line. Chromosome number variability was investigated in 102 regenerated plants. Mitotic root-tip cells were scored initially; those plants exhibiting mixoploidy or an altered chromosome number were reexamined at meiosis to confirm the presence of alterations in germ line cells. Plants regenerated from seedling explants included 2n = 38 diploids (87.0%) similar to the parental line, monosomics (7.8%), trisomics (2.6%), and 2n = 76 tetraploids (1.3%). The germ line number was not resolved in one mixoploid (1.3%). Protoplast-derived regenerated plants were diploid (44%), hypodiploid (20%), and tetraploid or hypotetraploid (36%). Meiotic analysis of regenerated plants showed a range of multiple chromosome associations with no plants consistently exhibiting bivalent formation only. Chromosomal alterations other than number may have been induced by culture, but could not be substantiated since multiple chromosome associations were also frequent in control plants grown from seed.Key words: plant regeneration, protoplast regeneration, Brassica napus, cytogenetics.


Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 929-934 ◽  
Author(s):  
P. Banks ◽  
E. J. Britten ◽  
G. H. Gordon

Germinating seeds of rape (Brassica napus L.) and of tomato (Lycopersicon esculentum Mill.), and 1-month-old tomato seedlings, were treated with para-fluorophenylalanine to change chromosome numbers. A number of morphological aberrations were found in treated plants of both species, some of which were also observed in progeny of treated tomatoes. Aneuploids and polyploids were confirmed cytologically in treated plants of both species. The investigations confirm the suggestion previously made for maize, that para-fluorophenylalanine is capable of changing chromosome numbers and the resulting morphology of plants of widely different phylogenetic categories.Key words: Para-fluorophenylalanine, chromosome number changes, plants, tomato, rape, aneuploids, polyploids, morphological changes.


1986 ◽  
Vol 28 (3) ◽  
pp. 330-334 ◽  
Author(s):  
T. Attia ◽  
G. Röbbelen

Newly resynthesized AC amphihaploids, which were characterized by high meiotic pairing and multivalent formulation, after doubling of their chromosome number showed preferential pairing and bivalent formation in the resynthesized amphidiploid Brassica napus (AACC). However, univalents as well as multivalents were also formed indicating that their chromosome behaviour was not fully diploidized. Stabilization of chromosome pairing in newly resynthesized amphidiploids can be achieved through genetic control or structural modification of the homoeologous chromosomes. A comparison of the meiotic behaviour of spontaneous haploids of natural rapeseed with that of the newly synthesized AC amphihaploids provides some evidence that both processes may be involved in the regulation of chromosome pairing in Brassica.Key words: Brassica, amphihaploid, amphidiploid, meiosis, univalents, multivalents.


Genome ◽  
1988 ◽  
Vol 30 (3) ◽  
pp. 450-457 ◽  
Author(s):  
William Tai ◽  
H. Ikonen

Twenty five polyhaploid plants (2n = 2x = 19, genome formula AC) of Brassica napus (2n = 4x = 38, AACC) were cytogenetically studied. Seven of these were found among field populations and the rest were derived through anther culture of B. napus cv. Regent. Meiotic behaviour at diakinesis and metaphase I revealed nine bivalents and one univalent in more than 40% of the more than 400 pollen mother cells analyzed. However, when the chromosome number of the polyhaploids was doubled using colchicine, 19 bivalents were observed. These doubled plants (2n = 4x = 38, AACC) also had normal behaviour identical to a regular B. napus at other meiotic stages. Quadrivalent associations were observed when the chromosome numbers were doubled to the octaploid level (2n = 8x = 72, AAAACCCC). It is suggested that A and C are homoeologous genomes. If homologous partners are present, chromosomes would pair within the same genome to form bivalents as occurred in the allotetraploids and to form quadrivalents as occurred in the allooctaploids. However, when a homologous partner is not available, the homoeologous chromosomes would then pair to form bivalents in those polyhaploids.Key words: Brassica napus, polyhaploids, genome relationship, meiotic behaviour, homoeologous pairing.


2019 ◽  
Vol 51 (6) ◽  
Author(s):  
Samrin Gul ◽  
Razi Uddin ◽  
Naqib Ullah Khan ◽  
Shahid Ullah Khan ◽  
Sardar Ali ◽  
...  

Author(s):  
Т. В. Шеленга ◽  
А. В. Конарев ◽  
Л. П. Бекиш ◽  
Л. Ю. Новикова ◽  
И. Н. Перчук ◽  
...  

Отмечена роль Н. И. Вавилова в организации исследований исходного и селекционного материала по биохимическим признакам, определяющим пищевые, кормовые и технологические качества сельскохозяйственной продукции. Выделен перспективный материал для создания сортов рапса с улучшенными пищевыми, кормовыми и технологическими характеристиками; выявлен характер зависимости признаков качества масла от погодных условий (температура, количество осадков и др.). Изучены 50 высокоэруковых (ВЭ) и 40 низкоэруковых (НЭ) линий ярового рапса (Brassica napus L.), выращенных в условиях Ленинградской области в 2012 – 2015 гг. Содержание масла и влажность в семенах определяли методом инфракрасной спектрометрии. Жирнокислотный состав (ЖКС) масла изучали с помощью газожидкостной хроматографии с масс-спектрометрией. Установлено содержание доминирующих жирных кислот для ВЭ и НЭ образцов, а также характер влияния погодных условий на ЖКС масла, в том числе на состав его отдельных фракций. Для ВЭ образцов установлена достоверная отрицательная корреляция (r = –0,96) между содержанием эруковой кислоты и температурой воздуха и достоверная положительная (r = 0,96) с количеством осадков в первую декаду июля. Для НЭ образцов установлена достоверная отрицательная зависимость между содержанием эруковой кислоты и средней температурой воздуха в мае. Выделенные образцы с высоким содержанием олеиновой (61,4 %) и низким линолевой (7,4 %) кислот можно рекомендовать для получения безэруковых сортов рапса, масло которых пригодно для длительного хранения. Контрастные по содержанию эруковой кислоты образцы будут использованы для создания сортов ярового рапса пищевого и кормового назначения, а также для производства биодизеля.


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