Cabbage: Origin, Taxonomy, Botany, genetics, cytogenetics, breeding objectives and methods

This is an overview of Origin, Taxonomy, Botany, genetics, cytogenetics, breeding objectives and methods of cabbage

1. Brassica oleracea var. capitata CABBAGE SAM HIGGINBOTTOM UNIVERSITY OF AGRCULTURE TECHNOLOGY AND SCIENCES Department of Genetics and Plant Breeding SHUATS Submitted to : Dr. G.M. LAL Assistant Professor Presented by : N. SANDEEP M.Sc. (GPB) 20MSCGPB122 HOVS-711

2. INTRODUCTION BOTANICAL NAME : Brassica oleracea var. capitata COMMON NAME : Gobi FAMILY : Cruciferae / Brassicaceae CHROMOSOME NUMBER : 2n = 2x = 18 ORIGIN : Europe

3. O RIGIN Origin -South and Western part of Europe N a ti v e t o Eu r o pe , g r o wing along t h e c o s t of t he North sea Annual world production -21million tones of fresh heads from 1.1 million hectares Cabbage was originated from a wild non-heading type plant Brassica oleracea var. sylvestris Syn. ( Brassica sylverstris ) commonly known as wild cliff cabbage or cole worts . The real headed cabbage was evolved in Germany. The savoy cabbage originated in Italy and spread to France and Germany in the sixteenth and seventeenth centuries. At present, cabbage is grown in Caribbean countries, Indonesia, Malaysia, Central East and West America.

4. BOTANY Roots - adventitious root system Stem - unbranched stem Leaves - arises as the growing point The outer leaves are green in colour and the inner ones are white As the plant grows, the leaves increase in number, forming a ball-shaped “head” Bud- formed by overlapping of numerous leaves developing over the growing point of its shortened stem

5. Inflorescence: Raceme, indeterminate growth Flower: Pedicellate, ebracteate, hermaphrodite, actinomorphic and tetramerous Floral formula: Calyx (sepals): 4 separate Corolla (petals): 4 separate, often clawed, cruciform Androecium: 6, tetradynamous (4 tall, 2 short) Gynoecium: 2 united carpels, superior ovary (= hypogynous flower); ovules have parietal placentation Floral characters

6. TAXONOMY COMMON NAME : Cabbage SCIENTIFIC NAME : Brassica oleracea var. capitata CHROMOSOME NUMBER  : 2n=2x=18 SCIENTIFIC CLASSIFICATION Kingdom Plantae Subkingdom Tracheobionta Superdivision Spermatophyta Division Magnoliophyta Class Magnoliopsida Subclass Dilleniidae Order Capparales Family Brassicaceae Genus Brassica  L. Species Brassica oleracea L. Variety Capitata

7. Cytology of Cabbage Cabbage has a somatic chromosome number of 18 and its genome is c It is a secondary polyploid with basic chromosome number 6 Three basic chromosomes are present in duplicate and remainder are single i.e. ABBCCDEEF = 9 Molecular genetic work, using restriction fragment length polymorphisms (RFLPs), suggests that this picture may be an over-simplification In the course of constructing an RFLP map in B. oleracea, there is evidence of duplicate loci which mapped to different chromosomes It might be difficult to identify the possible structure of a lower chromosome number progenitor or to determine if B. oleracea evolved by duplication of loci and complex rearrangements

8. This shows the interrelationships of various Brassica species, genome designations and chromosome numbers All these six Brassica species and radish (Raphanus sativus, 2n=18) have been intercrossed with great difficulty utilizing embryo culture. Thus, the amphidiploids originated in nature from crosses between the parental species

9. T he cabbage genome size is approximately 603 Mb As a diploid species,  B. oleracea  underwent a whole-genome triplication (WGT) event, followed by two whole-genome duplication (WGD) event and a specific WGT of the Brassicacea lineage, thus becoming a model for studies on polyploid genome evolution Currently, two  B. oleracea  genomes based on next-generation sequencing (NGS) technology are available: the TO1000 (kale-like;  B. oleracea  var.  alboglabra ) assembly and the 02-12 (cabbage;  B. oleracea  var.  capitata ) assembly, but their errors and gaps make them difficult to use for many studies. Recently,  B .  oleracea  L. var.  italica  (broccoli) genome assembly was completed using long reads and optical maps. Broccoli and cabbage belong to Brassica species, however their growth, morphology and molecular levels is extremely variable, showing the importance of generating several genome assemblies for different morphotypes of  B .  oleracea . Up to now, there is still no high quality, comprehensive assembled cabbage ( B. oleracea  var.  capitata ) genome, which hinders greatly basic genetics and genomics research, as well as crop improvement. Thus generating an accurate cabbage genome assembly is crucial. Genetics of Cabbage

10. This Figure shows different linkage groups present in the cabbage genome

11. BREEDING OBJECTIVES Higher yield Long e r staying c a p acity i n t he f i e l d after head formation Narrow, short, and soft core Shorter stem Cultivars suitable to grow under mild winter Storage ability Head compactness Contd ….

12. Resistance to diseases Club root ( Xanthomonas campestris ) Downy mildew ( Peronospora parasitica ) Fusarium yellows Leaf spots Leaf Blight ( Alternaria brassicola ) Ring spot Black rot Insect resistance From diamondback moth ( Plutella xylostella ) cabbage moth ( Mamestra brassicae ) cabbage root fly ( Delia radicum ) cabbage maggot ( Hylemya brassicae ) cabbage white butterfly( Pieris rapae )

13. Breeding Methods of Cabbage Open-pollinated Cultivars Hybrid Cultivars

14. Mass selection Inbreeding (in cultivars with low level of self-incompatibility and inbreeding depression) Open-pollinated Cultivars

15. The self-incompatibility is used to produce hybrid seeds in cabbage and other cole crops, namely, cauliflower, broccoli, Brussels sprouts, and kale. The individual plants are self-pollinated through bud-pollination. Selection is applied for desirable characters and strong level of self-incompatibility. This way several self-incompatible, but cross-compatible inbreds having different S-alleles are developed. Such S 1 S 1  and S 2 S 2  lines are planted in alternate rows in isolation and seed set on each line will be mostly hybrid seed where cross-fertilization is brought about by pollinating insects, mostly bees. The cross compatibility between inbreds of S 1 S 1  and S 2 S 2  assures the production of F 1  hybrid seed. Hybrid Cultivars Contd …

16. Cabbage hybrids could be of following kinds: Single Cross: This is a cross between two inbreds. Single cross hybrids are more uniform than hybrids produced from double/top crosses. Double Cross: A cross between two single crosses is known as double cross. Four homozygous inbreds are required to produce a double cross, for example, (S 1 S 1  x S 2 S 2 ) X (S 3 S 3  x S 4 S 4 ). In this system, seed is harvested from both the single crosses which themselves are vigorous and therefore, cost of hybrid seed is reduced. Top Cross: This is a cross between a single self-incompatible inbred line as female and a good open- pollinated cultivar as pollen parent. Till late eighties, most of the cabbage hybrids produced in United States were top crosses.

17. It is easy to breed self-incompatible lines of cabbage through continuous self-pollination and selection. When two self-incompatible lines are used as parents to produce hybrids, the reciprocal crossed seeds can be harvested as hybrids. In 1950, the first cabbage hybrid in the world was developed in Japan using self-incompatible lines. This hybrid was known as Nagaoka No. 1. Breeding b y Utilisation of Self-Incompatible Lines Contd ….

18. The superior self-incompatible lines for hybrid seed production should have following characters: 1. Stable self-incompatibility 2. High seed set after self-pollination at bud stage 3. Favourable economic characteristics 4. Desirable combining ability 5. Almost all cabbage hybrid seeds are produced using self-incompatible lines all over the world. Now CMS system is also being used.

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