NEW GENERATION HYBRIDS OF WHITE CABBAGE (Brassica oleracea L. convar. capitata var. alba DC) BASED ON DOUBLED HAPLOIDS

Abstract

A b s t r a c tPresently, cabbage breeding is mainly focused on F 1 hybrids necessitating constant parental lines to be obtained. Doubled haploid (DH) technology based on isolated microspore in vitro culture is widely used to produce pure lines of brassica crops. This method allows us to rapidly develop homozygous lines, in contrast to time-consuming traditional breeding for heterosis in cross-pollinating crops which takes 7 to 10 years for annuals and 14 to 20 years for biennial plants. One of the objectives of DH technology is to provide the all possible number of doubled haploid plants that allows more fully encompass the spectrum of genetic recombination, including the recessive locus. The aim of our study was to evaluate economically important traits in white cabbage (Brassica oleracea L. convar. capitata var. alba DC) constant doubled haploid lines of late ripening and to improve the technology for producing DH based F 1 hybrids. Eleven breeding lines of late ripening cabbage were used to obtain doubled haploid lines from microspore in vitro culture. Of the obtained lines, twelve doubled haploid genotypes were selected for further use based on evaluation of ploidy and combining ability. Seed progeny was reproduced by hybridization of regenerated plants in a climatic chamber (2014)(2015). We used the schemes of creating self-incompatible lines and two-line-based hybrids. In the field trials (Moscow region, 2014(Moscow region, -2015, the doubled haploids and their hybrid combinations were compared to the standard (Severyanka F 1 ) for the main valuable characteristics (i.e. the content of dry matter, nitrates, and vitamin C). The field resistance to Fusarium wilt, alternariosis, and pest damage were determined at cabbagehead technical maturity. The resistance to clubroot was assessed under artificial infection. There was a direct relationship of the average number of chromosomes to the number of chloroplasts in the stomata guard cells and the length of guard cells. The frequency of spontaneous doubling of the chromosomes numbers varied from 50.0 % to 87.5 % in different geotypes. A total of 11 to 73 % produced lines were high self-incompatible. Their geitonogamic pollination in the topcrosses resulted in 42 hybrid combinations. The model of F 1 hybrid most fully responding to consumer market demands was developed. Ten promising hybrid combinations which matched the model parameters in two-year field testing were recommended for variety testing. Hybrids were characterized by uniformity, high biochemical quality, the resistance to major diseases and pests and the yield of 104.60±8.27 t/ha. The dry matter content reached to 10.5 %, the sugar content was about 4.21-5.10 %, and ascorbic acid level ranged from 21.12 to 38.70 mg%. Both the highest level of ascorbic acid (92.0 mg%) and the smallest nitrate accumulation (33 mg/kg) were characteristic of one hybrid combination.Keywords: white cabbage, Brassica oleracea L., doubled haploid lines, heterosis F 1 hybrids, in vitro isolated microspore culture, self-incomp...

ANTHER-DERIVED CALLUS FORMATION IN BITTER MELON (Momordica charantia L.) AS INFLUENCED BY MICROSPORE DEVELOPMENT STAGE AND MEDIUM COMPOSITION

“…В связи с этим DHтехнологию необходимо оптимизировать для конкретной культуры и даже генотипа. Особенно это актуально для овощных культур (17).…”

GENERATION OF Rubus arcticus L. HAPLOIDS THROUGH in vitro MICROSPORE CULTURE TECHNIQUE

“…Проведенные исследования не позволяют идентифицировать, на какой именно стадии развития микроспоры лучше получать гаплоидные растения княженики, однако это имеет важное значение для определения факторов, влияющих на переключение программы развития микроспоры с гаметофитной на спорофитную (17,19,28,32). Можно только отметить, что большая часть микроспор находилась на стадии вакуолизации.…”

“…2). Многие авторы отмечают положительное влияние повышенного осмотического давления, которое создается при концентрациях сахарозы от 10 до 17 %, на появление эмбриоидов (26)(27)(28), однако в наших опытах эмбриоидогенез у R. arcticus активно происходил при концентрации 3 %, а уже при 4 % скорость развития уменьшалась. Такое расхождение в результатах может объясняется тем, что мы изучали этап перехода от стадии эмбриоида к растению-регенеранту, а не этап образования эмбриоида из микроспоры.…”

Utilizing Ogura-CMS and doubled haploid lines of cabbage for new-generation hybrid breeding

“…With these constraints, DH technology based on isolated microspore in-vitro culture is widely used to produce complete homozygous lines of Brassica crops (Bhatia et al 2016). This method allows us to rapidly develop homozygous lines, in contrast to time-consuming traditional breeding for heterosis in cross-pollinating crops which takes about seven to ten years (Pivovarov et al 2017). To date, very meager information is available in the literature on genetic diversity analysis using CMS and DH lines of cabbage and their exploitation for uniform hybrid development in cabbage.…”