Cauliflower

breeding of cauliflower

1. Breeding of Cole crops :Cauliflower Tejaswini Uppuluri I Ph.D , Seed science and technology UAS, GKVK, Bengaluru

2. The name cauliflower consists of two Latin words, ‘caulis’ and ‘ floris ’, former means cabbage and the later means flowers. It is originated from wild cabbage known as ‘Cole warts’, through mutation, human selection and adoption. The edible part of cauliflower is known as curd, which consists of a shoot system with short internodes, branches apices and bracts. Nutrition status: It has high quality of proteins and peculiar in stability of vitamin C after cooking. It is rich in minerals such as potassium, sodium, iron, phosphorus, calcium, magnesium etc. It also contains vitamin A. Cauliflower contains 92.7 per cent water and the food value per 100 g of edible ascorbic acid 70 mg, thiamine 0.2 mg, riboflavin 0.1 mg and niacin 0.57 mg. Introduction Nath,1976

3. Cauliflower seedlings are used for salad and green. The curd is used in curries, soups, and pickles. In abundant areas of production, cauliflower curd is cut in to pieces, dried and preserved for off-season use. The inflorescence extract has been used in the treatment of scurvy, as a blood purifier and as an antacid. Cauliflower extract has been reported to be effective in the inhibition of initiation and promotion of carcinogenesis in in vitro. Potential chemo preventive agents include ascorbic acid, carotenoids , tocopherols , isothiocyanates , indoles and flavonoids . Importance

4. Per 100 g of Cauliflower Vitamin K 73.35 mcg Vitamin C 30.15 mg Dietary fiber 3.45 g Manganese 0.18 mg Vitamin B6 (pyridoxine) 0.17 mg Folate 30.00 mcg Omega 3 fatty acids 0.17 g Vitamin B1 (thiamin) 0.09 mg Vitamin B2 (riboflavin) 0.08 mg Calcium 46.50 mg Potassium 145.50 mg Vitamin A 198.00 iu Tryptophan 0.01 g Protein 1.53 g Magnesium 12.00 mg Nutrient content

5. Scientific classification Kingdom - Plantae Phylum - Tracheophytes Class - Angiosperms Order - Brassicales Family - Brassicaceae Genus - Brassica Species - oleracea Binomial nomenclature - Brassica oleracea var. botrytis Chromosome number - 2n = 2x= 18 Origin - Coastal area of the Mediterranean Sea. Genome - CC Ancestor - Brassica olearcea var. sylvestris

6. Origin and Distribution European cauliflower Systematic and extensive cultivation of cauliflower occurred first in Italy where the ‘Originals’ or ‘Italians’ were developed. These ‘Original’ or ‘Italian’ types were taken to France, England, Germany and the Netherlands. The Indian/tropical cauliflowers grown in India are characteristically different from European types and are tolerant to high temperature and humid conditions—the earliest maturing types known—and do not require vernalization for bolting. The top 10 producing countries are China (35.77%), India (34.49%), Mexico (2.13%), France (1.56%), Italy (1.36%), Poland (1.23%), the United States (1.16%), Pakistan (1.07%), Germany (0.53%), and Egypt (0.48%). The important Indian states producing cauliflower are West Bengal, Bihar, Maharashtra, Madhya Pradesh, Odisha , Gujarat, Haryana, Chhattisgarh, Jharkhand, Assam, and Uttar Pradesh.

7. Evolution

8. Raceme type of inflorescence, with hermophrodite flowers. 4 sepals, free, in two whorls. 4-petals.free in one whorl,alternate , Tetra dynamous , two carpels , syncarpous . ovary superior-two celled. Many ovules in each cell with Parietal placentation . Botany  There are 4 sepals, 4 petals, 6 stamen .  The carpels form a superior ovary with false septum and two rows of campylotropous ovules. The androecium is tetradynamous , i.e. there are two short and four long stamens.  The sepals are erect.  The nectar is secreted by two nectaries situated between the basis of the short stamens and the ovary.

9. Floral Description  The flowers of cauliflower are typically cruciferous.  Two functional nectaries are present, situated between the bases of the ovary and short stamens and the other two inactive nectaries are at the bases of pairs of long stamens.  The stigma of Brassica species is receptive for 5 days before and 4 days after anthesis .  The longer receptivity is due to the protogynous nature of the flowers.  Situated outside the basis of the pairs of long stamens are also two nectaries , but these are not active. Flowers are borne in racemes on the main stem and its branches.  The inflorescence may attain a length of 1-2 cm, but the slender pedicels are only 1.5-2 cm long.  The fruits are glabrous siliques , 4-5 mm wide and sometimes over 10 cm long, with two rows of seeds lying along the edges of the replum (false septum, an outgrowth of the placentae ).  A silique contains from 10-30 seeds, the silique reaches its maximum length. When it is ripe, dehiscence takes place through the two valves breaking away from below upwards, leaving the seeds attached to the placentas.

10. The pollen grains are 30-40 μ in diameter and have three germination pores. The bright yellow petals become 15-25 mm long and about 10 mm wide. The sepals are erect. The buds open under the pressure of the rapidly growing petals. This process starts in the afternoon, and usually the flowers become fully expanded during the following morning. The anthers open a few hours later, the flowers being slightly protogynous . The flowers are pollinated by insects, particularly bees, which collect pollen and nectar. The nectar is secreted by two nectaries situated between the basis of the short stamens and the ovary. Situated outside the basis of the pairs of long stamens are also two nectaries , but these are not active. Flowers are borne in racemes on the main stem and its branches. The inflorescence may attain a length of 1-2 m, but the slender pedicels are only 1.5-2 cm long. The fruits are glabrous siliques , 4-5 mm wide and sometimes over 10 cm long, with two rows of seeds lying along the edges of the replum (false septum, an outgrowth of the placentae ). A silique contains from 10-30 seeds. Three to four weeks after the opening of the flower from which it is formed, the silique reaches its maximum length. When it is ripe, dehiscence takes place through the two valves breaking away from below upwards, leaving the seeds attached to the placentas. Pollination

11. Pollination Technique of Cauliflower : Selfing : The self-compatible varieties of cauliflower can be selfed by simply bagging the flowering stalk. Selfing is also done by caging some plants with flies in cages or by isolation planting of lines having decreased level of self-incompatibility. With self-incompatible plants, bud pollination gives better results. In this system, the pollination is carried out in buds before 2-4 days of opening, with emasculation or without emasculation. Crossing: The flowers may be emasculated by removing 6 stamens using a pair of forceps. In self- compatible cauliflowers (European types), the stamens are removed before the opening of the buds as the flowers are already fertile in the bud stage, crossing can be done at the same time. In self-incompatible types, emasculation may be omitted. When pollination cages are available, crosses between self-incompatible types can be made by insects such as honey bees, bumble bees and flies.

12. Self-incompatibility Homomorphic system type Sporophytic self incompatibility (SSI) i.e. in Cauliflower it is confirmed by ( Hoser-krauze 1979 ). It is controlled by single s-locus with multiple allele but also reported more than one loci, more than 80 s-alleles reported in Brassica family. A classical genetic analysis has grouped the Brassica S-alleles into two categories based on their phenotypic effect on self-incompatibility characteristics. First group of alleles High activity Second group of alleles Low activity The first group of alleles (high-activity) are placed relatively high on the dominance scale and exhibit a strong self-incompatible phenotype in which an average of 0 to 10 pollen tubes develop per selfpollinated stigma The second group of alleles (low-activity) demonstrate a weak or leaky self incompatible phenotypic effect in which 10 to 30 pollen tubes develop per self-pollinated stigma and they are considered to be recessive ( Nasrallah et al. 1991) The compatible and incompatible reaction of pollen and stigma depends on Genotypes (homozygous/heterozygous) of male and female plant at S locus Interactions between the two S alleles  Dominance ( S1 > S2)  Co-dominance ( S1 = S2)  Mutual weakening (no action by either allele)  Intermediate gradation (1-100% activity by each allele) Molecular Mechanism of SSI ( Takayama and Isogai 2005) 12

13. Male sterility Male sterility systems usually carry nuclear and mitochondrial genomes; that is, genic male sterility (GMS) and cytoplasmic male sterility (CMS), respectively. Use of biotechnological tools provides another type of male sterility, transgenic male sterility (TMS). GMS Male sterility The GMS in cole crops are mainly recessive. A single recessive gene ms, a mutated form of the male fertile Ms gene, occurs in cauliflower. Monogenic-dominant male sterility has been described in cauliflower. This has limited possible practical value in hybrid seed production in some cauliflowers because of the unreliable nature of the SI system. Some forms of GMS are temperature sensitive and result in self-pollination. 13

14. The CMS has not been identified in cauliflower or other cole crops but has bee introduced from R. sativus , B. nigra , B. napus , B. juncea and B. tournefortii . CMS has been transferred in broccoli through repeated backcrossing. The Ogura-type CMS has been transferred into heat-tolerant Indian cauliflower from kale and broccoli and is being used in heterosis breeding. Chiang and Crete (1987) introduced CMS from B. napus into cabbage and later from cabbage to cauliflower. The CMS system is an ideal solution for hybrid development because crosses between a male sterile plant and a hermaphrodite plant (homozygous for maintainer alleles) give rise to 100% male sterile plants. Improvement of female fertility and cold tolerance via protoplast fusion ( Jourdan et al., 1989; Pelletier et al., 1983) made the Ogura CMS system the most popular one used for modern breeding of broccoli, cauliflower, and cabbage F1 hybrids. In India, Ogura CMS is used to transfer the MS system in tropical and Snowball cauliflower. The Ogura CMS lines of cauliflower, Ogu1A, Ogu2A, Ogu3A, Ogu12A, Ogu13A, Ogu14A, Ogu16A, and Ogu33A, have been developed.

15. Tapetal -specific expression of a ribonuclease inhibitor gene barstar in the male parent restores fertility to hybrid plants. This technology is linked with the selectable marker phosphinothricin acetyltransferase conferring tolerance to the herbicidal active ingredient glufosinate ammonium. Timely application of herbicide is essential to remove nontransgenic plants, which adds to cost and complexity. The TMS is a biotechnology-based process developed to propagate seed of homozygous male-sterile female inbred lines. One of the first biotechnology based approaches to male sterility, TMS was proposed by including tapetal specific expression of a ribonuclease gene barnase to cause complete male sterility. The specific expression of the cytotoxin can selectively destroy organs or tissues related to pollen development, block the development process, and lead to male sterility. RNase digests RNAs. The genes encoding Rnase - barnase and RNase T1—have been cloned. The RNase gene and a specific promoter can be linked and transferred into plants to obtain male sterile plants. The fused TA29, the tapetum -specific promoter isolated from tobacco anthers, with the barnase gene from Bacillus amyloliquefaciens and with the RNase T1 gene to be introduced into tobacco and oilseed rape through genetic transformation. They demonstrated introduction of male sterility in transgenic tobacco a nd B. napus plants. Genes coding for ribonucleases were transferred independently, RNAase-T1 from Aspergillus oryzae and Barnase from Bacillus amyloliquefaciens . These genes, under control of the TA29 promoter 9, are expressed in the tapetal cells. TMS has been developed in various crops, including cauliflower. There is no need to introduce the barstar gene in male parents of those crops where sexual reproduction is not required for development of economic parts used.

16. Public hybrids developed in Cauliflower Self-incompatibility Name of the hybrid Type of Genetic Mechanism (Parentage) Developing Institution Pusa Hybrid-2 (Nov maturing, Group-II), Pusa Kartik Sankar (group-I) Self-Incompatibility ( Pusa Hybrid-2=CC x 18-19) ( Pusa Kartik Sankar = CC 14 x 41-5) IARI, New Delhi Xiahua 6 ( heatresistant ) Self-Incompatibility Xiamen Agricultural Research Institute of Sciences, China, 2006 16

17. Private hybrids developed in Cauliflower 17

18. Classification of cauliflowers Swarup and Chatterjee (1972) classified the cauliflower varieties in various groups. Cauliflower type Country of origin Probable period of first cultivation Characters Italian or original Mediterranean 16 th Century Plants short; leaves erect broad with rounded tips, bluish green, curds good not protected. Cornish England Early 19 th Century Plants vigorous, long stalked; leaves loosely arranged, broadly wavy; curds flat; irregular, loose, not protected, yellow, highly flavoured. Northerns England 19 th Century Leaves petioles, broad, very wavy, serrated; curds good, well protected. Angers France 19 th Century Leaves very wavy, serrated, grayish green, curds solid and well protected.

19. Cauliflower type Country of origin Probable period of first cultivation Characters Roscoff France 19 th Century Plants short; leaves long erect, slightly wavy with pointed tip, midrib prominent, bluish green; curds white or creamy, hemispherical and well protected. Erfurt and snowball Germany and Netherlands 18 th Century Plants dwarf; leaves short, erect, curds solid and well protected. Indian cauliflower India Late 19 th Century Plants short, long stalked; leaves loosely arranged, broadly wavy; curds flat, somewhat loose, yellow to creamy, not protected and highly flavoured.

20. Crisp (1982) has also classified the groups of cauliflower according to the phylogeny Group name Characteristics Common type Italian Very diverse, include both annual and biennials and curds with peculiar conformations colors . Jezi , Naples (Autumn Giant), Romanesco and Flora Blanca. North European annuals Developed in Northern Europe for at least 400 years. Origin unknown, perhaps Italian Eastern Mediterranean. Alpha, Mechelse , Erfurt and Danish North West European biennials Developed from Italian material with in 300 years Angers, old English, Roscoff St. Malo , Walcheran . Asian Recombinants of European annuals and biennials, developed within last 250 years, adapted to tropics Four maturity groups are recognized by Swarup and Chatterjee (1972). Australian Recombinants of European annuals and biennials and perhaps Italian stock, developed during the last 200 years. Not yet been categorized

21. Classification of Cauliflower on the Basis of Maturity Maturity Varieties Temperature requirement for curd initiation and development Early (September maturity) (October maturity) Early Kunwari , Pusa Early synthetic, Pusa Deepali 20 o C - 27 o C Mid October-Mid November Pant Gobhi-2 20 o C - 25 o C Mid Early Improved Japanese 16 o C - 20 o C November maturity Mid November-Mid December Pusa Hybrid-2, Pusa Hybrid-3 Pusa Sharad , Pant Gobi-4 Mid Late December maturity (Mid December-Mid January) Pusa Synthetic, Pusa Shubra, Pusa Himjyoti , Punjab Giant-35 12 o C - 16 o C Late Snowball Pusa Snowball-1, Pusa Snowball K-1 10 o C - 16 o C

22. Breeding objectives High yield along with better crop ideotypes . Uniform curding; that is, uniformity in curd size, shape, maturity, and color . Compact and retentive white curds free from riceyness , leafiness, and fuzziness. High commercial quality as determined by size and shape, appearance, color persistence, compactness, and bruise resistance. Small curds with smaller frame size for dense transplanting. High harvest index, wide adaptability, and better field standing ability. Tolerant to heat/humidity; that is, curd formation in summer/rainy seasons of northern India. Robust SI and CMS lines to produce hybrids with better seeding ability. Cultivars tolerant to the diseases black rot, Sclerotinia rot, downy mildew, Alternaria blight, Erwinia rot; insects DBM, Spodoptera ; and abiotic stresses including heat, rain, salt.

23. Curd Quality: Primarily determined by compactness and colour. It should be compact and retentive white. The curd colour of Indian cauliflower is yellowish to creamish white while the Snowball is bright white. A major defect of curd is riceyness caused by precocious and frequently uneven development of flower bud initials over the curd surface. Ricey curds are regarded as undesirable for market, in nature the precocious formation of flower buds is advantageous because it assists the ultimate expansion and development to flowering so that plants with ricey curds set seed more easily than those with perfect curd. Grading in Cauliflower Grade 1 – Perfect, Grade 2 – A few projections on each whorl but perfect when held at arms length, Grade 3 – Clear patches but many elongated buds, furry all over, Grade 4 – Well-formed buds over whole surface Although this phenomenon has no effect on the taste, it is nevertheless looked upon as a serious fault. Little is known about the influence of the environment on the incidence of riceyness , though its occurrence is sometimes related to high temperature.

24. Genetic resources Genetic resources provide diversity necessary for genetic improvement. The genetic resources are conserved as ex situ (gene banks) and in situ populations ( center of origin, diversity, and domestication or place of cultivation). Molecular resources are also increasingly useful, including expressed sequence tags, full-length cDNA clones of many genes, and bacterial artificial chromosome libraries ( Maggioni , 2015). In worldwide, more than 20,000 accessions of C-genome taxa of B. oleracea are conserved in more than 100 gene banks in various countries. In India, the Indian Council of Agricultural Research–Indian Agricultural Research Institute (ICAR-IARI) Regional Station, Katrain , Himachal Pradesh, ICAR-IARI, New Delhi; ICAR–National Bureau of Plant Genetic Resources, New Delhi; ICAR–Indian Institute of Vegetable Research, Varanasi, Uttar Pradesh; Dr. Yashwant Singh Parmar University of Horticulture and Forestry, Solan , Himachal Pradesh; and some private seed companies are doing genetic improvement and maintaining germplasm of B. Oleracea .

25. Population Improvement Methods and Hybrid Breeding - Heterosis Without Progeny testing - Mass selection, stratified mass selection Progeny testing - Recurrent selection, Family breeding, Pedigree method, Back cross method, Line breeding. 2. Development of inbreds as Cultivars 3. Biotechnological breeding : Transgenic Cauliflower Double haploids Crop ideotypes Breeding for resistance to biotic stresses Breeding Methods of Cauliflower

26. Mass selection: In this method the best individual plants are selected in the population and their seeds are composited for following generation. Since the mass selection is made exclusively based on the phenotype of the plants without any progeny testing, the success of selection depends upon the heritability of the characters under selection. EX: Early kunwari , Pusa katki Introduction Introduced materials may be valuable in selecting desirable plants. In case of non-uniform introductions the desirable plants can be selected, their progeny increased, purified and later tested against the standard or local varieties for selecting the most promising lines. The chances of an introduction depends to a great extent upon the relationship between the agro climates, particularly temperature and day length of the donor and receptor areas. Family breeding There is elaborate testing of progenies not only in F1 generation but also in later 2 or 3 generations and usually more than one cycle of selection. This method is practised in beet and can also be adopted in radish, carrot and cauliflower.

27. Pedigree method It starts with the crossing of two genotypes, each of which have one or more desirable characters lacked by the other. If the two original parents do not provide all of the desired characters, a third parent can be included by crossing it to one of the hybrid progeny of the first generation (F1). In the pedigree method superior types are selected in successive generations, and a record is maintained of parent–progeny relationships. When the number of families has been reduced to manageable proportions by visual selection, usually by the F7 or F8 generation, precise evaluation for performance and quality begins. The final evaluation of promising strains involves (1) observation, usually in a number of years and locations, to detect weaknesses that may not have appeared previously; (2) precise yield testing; and (3) quality testing. Pusa shubra : (MGS 2-3X15-1-1)X D 96, Pusa snow ball 1 : (EC 12012X EC 12013) The bulk-population method   The breeding differs from the pedigree method primarily in the handling of generations following hybridization. The F2 generation is sown at normal commercial planting rates in a large plot. Two types of artificial selection also are often applied: (1) destruction of plants that carry undesirable major genes and (2) mass techniques such as harvesting when only part of the seeds are mature to select for early maturing plants or the use of screens to select for increased seed size. The chief advantage of the bulk population method is that it allows the breeder to handle very large numbers of individuals inexpensively. 27

28. RECURRENT SELECTION It is a better option for improvement of quantitative characters, especially those under control of additive gene action. This method has been effective for improvement of curd compactness, yield and other economic traits in cauliflower. Significant improvement in yield (18%–47%) and diameter, depth, and weight of curd after one generation of recurrent selection has been reported ( Tapsell , 1989). In India, variety Pusa Sharad , mid-maturity group, has been developed using recurrent selection (S. R. Sharma et al., 1999). The inbred lines can be obtained by overcoming SI barriers, either with BP or with chemical induction methods ( NaCl or CO2). The DHs are used to develop parental inbred lines. Use of inbreds as cultivars is mostly applicable to summer European types that have self-compatibility. In this approach, two self-compatible lines are crossed and the hybrid progeny is subjected to a simple pedigree/bulk/backcross method of breeding.

29. Combination breeding/ Back cross method It has been used to transfer genes of interest through backcrossing. The donor parent is crossed to the recurrent parent followed by progenies that are then crossed to the recurrent parent. The progeny of this cross is selected for the trait of interest and crossed back to the recurrent parent. This process is repeated for as many backcrosses as needed to create a line that is the recurrent parent with the gene of interest from the donor parent. The goal of backcrossing is to obtain a line as identical to the recurrent parent with the addition of a gene of interest. This method was used to develop ‘ Pusa Shubhra ’, which is resistant to black rot, curd blight, and riceyness (R. Singh et al., 1993), and to develop CMS lines.

30. Heterosis breeding The hybrid varieties are developed by exploiting the dominance variance in heterosis breeding. Hybrids are available for commercial cultivation in all the cross pollinated crops like cole crops and cucurbits etc. For the last two decades, vegetable breeders in India diverted their attention toward the development of hybrids and disease resistant varieties/hybrids. Vegetables have great potential for export and after value addition these can become an important commodity of agricultural export out of India. Heterosis breeding is based on the principle of selecting parents, developing homozygous inbred/SI/CMS lines, testing combining ability, evaluating cross-combinations and production of commercial F1 seed. The F1 hybrids offer positivity, uniformity, and consistency of vigor , yield, and quality and are produced by crossing two or more inbred parental lines (B.K. Singh and Singh, 2016). Heterosis in cauliflower was first reported by Jones (1932) . At present, open pollinated (OP) varieties of cauliflower have largely been substituted by F1 hybrids. Production of F1 hybrids is now developing faster, with some technical difficulties, using improved Ogura CMS and DH parental lines. Nieuwhof and Garretsen (1961) failed to find an appreciable amount of heterosis in European summer cauliflower (‘Snowball’, ‘Erfurt’, ‘Alpha’), which may be due to their narrow genetic base. Watts (1965) and Swarup and Pal (1966) found a significant amount of heterosis in ‘Snowball’ cauliflower. Swarup and Chatterjee (1972) investigated heterosis in Indian cauliflower and reported better manifestation of it in the first maturity group > second maturity group > third maturity group.

31. Development of synthetic varieties is based on exploitation of additive genetic variance. In a synthetic variety, unlike a variety developed by mass selection or line breeding, the desirable lines with selected genotypes are synthesized after testing their general combining ability. Synthetic varieties are produced in all Brassica vegetables after testing the inbred lines’ general combining ability. Generally, four to eight lines are selected for developing synthetics. The advantages of synthetic varieties are that its seed can be easily produced through open pollination; it is particularly useful where commercial seed industries are not developed; and it serves as a reservoir of germplasm . The cultivars Pusa Early Synthetic and Pusa Synthetic have been developed by synthesizing six and seven parents, respectively Synthetics

32. Development of inbred lines Inbred A nearly homozygous line obtained through continuous inbreeding of a cross- pollinated species with selection accompanying inbreeding. Resultant of inbred lines Top cross: Cross between an inbred line and an open- pollinated variety Test cross : Cross between F1 and homozygous recessive parent. Single cross : A x B Double cross:(A x B) x (C x D) Three way cross : (A x B) x C , Variety cross : A cross between two varieties The inbred lines can be obtained by overcoming SI barriers, either with BP or with chemical induction methods ( NaCl or CO2). The DHs are used to develop parental inbred lines.

33. Black rot ( Xantomonas campestris pv . campestris ), Alternaria blight ( Alternaria brassicicola ), downy mildew ( Pernospora parasitica ), watery soft rot ( Sclerotinia sclerotiorum ), club root ( Plasmodiophora brassicae ), Verticillium wilt ( Verticillium longisporum ), Fusarium yellows ( Fusarium oxysporum , F. conglutinanas ), soft rot ( Erwinia carotovora ), turnip mosaic virus, powdery mildew ( Erysiphae polygoni ), and bottom rot ( Rhizoctonia solanai ) are diseases affecting cultivation of vegetable brassicas . Breeding for multiple disease resistance is an important objective. Breeding lines have been developed with resistance to black rot, possibly the most serious disease of brassicas worldwide. ‘ Pua Kea’ and ‘S. No. 445’ (resistant); and ‘S. No. 246’, ‘S. No. 15’, ‘EC 12013’, and ‘EC 12012’ (susceptible–highly susceptible) and suggested that backcross breeding should be adopted or to attempt selection in the progeny of a cross made between two resistant parents for evolving highly resistant lines. A segregation analysis of F2 progeny of a cross between ‘ Pusa Himjyoti ’ (susceptible) and ‘ BR-161 ’ (resistant) indicated a single dominant locus governed resistance to Xcc race 1 and observed seven differentiating polymorphic markers. In B. incana , the presence of trichomes is likely responsible for the observed resistance to insects ( Vosman et al., 2015). Resistance to biotic stress

34. Transgenic crops, commonly referred to as genetically modified crops, enable breeders to bring favorable genes, often previously inaccessible, into already existing elite cultivars, improving their value and offering unique opportunities for enhancing quality, modifying morpho - phyisio -biochemical properties, and increasing tolerance to biotic (viral, bacterial infections, pests, and weeds) and abiotic (drought, frost, temperature, salt, ultraviolet rays) stress. Several strategies, including transgenic, have been used and developed to build resistance to these stresses in plants. Among insect pests, the lepidopteran larvae are the most problematic of vegetable brassicas worldwide. The cry genes, cry1A, cry1Ab, cry1Ac, cry1A(b), cry1Ab3, cry1Ba1, cry1C, cry1Ba1, cry1Ia3, and cry9Aa, from Bt have been introduced into Brassica vegetables. Chitinase genes cloned from plants and fungi have been transferred into vegetable Brassica that confer a broad range of resistance to Alternaria blight, black rot, and soft rot. In addition, various genes are effective against fungal pathogens by employing glucanase to wire stem, thionin to Alternaria blight, permantis to damping-off and osmotin to white rust. Various transformation approaches have been used in cauliflower, cabbage, and Chinese cabbage to induce TMS. Transgenic

35. In the classic breeding approach, production of F1 hybrids on a commercial scale is largely based on inbreds that are selfed and selected through six to eight generations of inbreeding, which is tedious because of SI in B. oleracea crops. The doubled haploids (DHs), produced by microspore culture, are an ideal strategy to maintain parental lines because they generate inbred lines with 100% homozygosity only in one generation and are efficient in accelerating breeding, developing new varieties, conducting basic genetic studies, and saving time. Microspore culture technology has been applied in Brassica breeding since the first report of successful isolation and culture of microspores in B. napus ( Lichter , 1982) and in broccoli (Keller and Armstrong, 1983). There have been advances in microspore culture of different Brassica species, especially cauliflower ( Gu et al., 2014). Double haploid

36. Most plant breeding is based on selection of superior traits and/or elimination of inferior traits. An additional approach is available through breeding of crop ideotypes . that is, plants with model characteristics known to require minimum resources, optimize morpho - physio -biochemical traits, and produce higher yield. On the basis of genetic stocks available in the Indian cauliflower, it is possible to determine the most desirable ideotypes in cauliflower as having specific maturity with 75%–80% uniformity; 12- to 15-cm stalk length; plant type of No. 3 (self-blanch leaves); 40- to 50-cm frame size; 18–22 leaf number; 50- to 55-cm leaf length; hemispherical curd shape; 15- to 18-cm curd diameter; 600–1000 g curd weight; 55–65 days of maturity; creamy white to white- colored curd; compact curd; devoid of riceyness , leafiness, fuzziness; and resistance/tolerance to black rot, Alternaria blight, diamond back moth (DBM; Plutela xylostella ), and Spodoptera . Crop ideotypes

37. Selection Against Bracting Defect : Bracts grow through the surface - papillae appearance - reduces commercial value. Its value is further reduced if the bracts develop green or purple coloration. Assessment of bracting – microscopically – impracticable in large scale. BREEDING FOR CURD QUALITY Breeding against Ricyness : Riceyness relatively consistent and is induced by cold temperatures. That is why cauliflower varieties bred in tropical produce ricy curds if grown under cool conditions. This defect has been shown to be highly heritable, monofactorial and hence highly responsive to selections (Crisp and Tapsell , 1993). Breeding for optimum Leaf Geometry : Discoloured or yellow heads of cauliflower fetch less price. Need for varieties having upright leaves. Plant type 3 is best backcross.

38. Cauliflower breeding for enhancing production and productivity and efficient use of input resources are the following: (1) Population improvement to increase sustainability of production, enhance nutritional quality, and reduce waste for which development of resistances to major abiotic and biotic stress are recognized. (2) Efforts should be made to integrate two- or multitiered breeding approaches for broadening the genetic base and introgressing genes and QTL of resistance, quality, and productivity into elite backgrounds. (3) Difficulties in commercial seed production of F1 hybrids need to be overcome by developing robust SI, Ogura CMS, and DH parental lines; modern breeding techniques; and proper management of pollinators. (4) Rapidly growing knowledge of advance tools of parental line development, molecular markers, and biotechnological interventions need enhanced utilization to improve precision and extend options to support future breeding of cauliflower. Future strategies

39. Diseases, Pests and control Pests Nature of damage Control Aphids Swarms of insects attack leaves, flowers, pods and suck the sap Spraying of Chloropyriphos @2 ml/ litre water Diamond back moth Small caterpillar attack the inner surface of the leaves and suck on them Chloropyriphos / Ripcord 50 EC@ 2 ml/litre of water Diseases 1. Club root Dipping the seedlings in Carbendazim solution (1 – 2 g/lit) for two minutes. 2. Leaf Spot Spraying of Carbendazim @ 1 g/lit. 3. Leaf Blight Spray of Mancozeb @ 2.5 g/ litre.

40. 1. Browning or brown rot This is caused by Boron deficiency. It appears as water soaked areas and later changes into rusty brown. Spray one kg of Borax in 500 lit of water 30 days after planting. 2. Whip tail This results from the deficiency of Molybdenum. It is more pronounced in acidic soil. The leaf blades do not de and it can be corrected by spraying 100 g of Sodium molybdate in 500 lit of water 30 days after planting. Physiological Disorders

41. Thank you