Abstract:
The invention relates to a fodder radish. More particularly, a fodder radish ( Raphanus  species) suitable for use as a multiple grazing fodder crop for livestock is provided. The invention also relates to the seeds, and to the plants of the radish. It also relates to methods of producing a  Raphanus  plant type having the characteristics of recovery from grazing to give the potential for multiple grazings over many cycles.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims priority from Australian Patent Application No. AU 2003903841, filed on May 24, 2003. 
   All of the foregoing applications, as well as all documents cited in the foregoing applications (“application documents”) and all documents cited or referenced in the application documents are incorporated herein by reference. Also, all documents cited in this application (“herein-cited documents”) and all documents cited or referenced in herein-cited documents are incorporated herein by reference. In addition, any manufacturer&#39;s instructions or catalogues for any products cited or mentioned in each of the application documents or herein-cited documents are incorporated by reference. Documents incorporated by reference into this text or any teachings therein can be used in the practice of this invention. Documents incorporated by reference into this text are not admitted to be prior art. 
   FIELD OF THE INVENTION 
   The invention relates to a fodder radish. More particularly, a fodder radish ( Raphanus  species) suitable for use as a multiple grazing fodder crop for livestock is provided. The invention also relates to the seeds, and to the plants of the radish. It also relates to methods of producing a  Raphanus  plant type having the characteristics of recovery from grazing to give the potential for multiple grazings over many cycles. 
   BACKGROUND OF THE INVENTION 
   Animal producers worldwide use fodder crops as an inexpensive means of feeding animals during times of forage shortfall, usually during dry summer periods or during cold winter periods. Fodder crops which can be grazed many times rather than once only have potential to lower the cost of production for many farmers. 
   Plants of  Raphanus  are used widely throughout the world for many purposes. 
   For example,  Raphanus sativus , domestic radish is used as a vegetable for human consumption, predominantly the root but also to a lessor extent of the leaves, stems and pods. 
     Raphanus sativus  can also be used as an oilseed crop where the seed is harvested and oil extracted. The sprouted seed may also be consumed as a sprout by humans. 
     Raphanus sativus  is also used as a biofumigant in crop rotations to suppress pathogens such as fungal diseases, or cyst nematodes in subsequent crops particularly with Sugar Beet ( Beta vulgaris ) in Europe. These crops are frequently ploughed under but may also be grazed once. 
     Raphanus sativus  may be used as a single grazing fodder crop. However, the cultivars used will usually not recover sufficiently from grazing to allow multiple grazings. Many of these cultivars are relatively early to flower, bolting with 3 months of sowing. The cultivars usually also have hairy leaves and stems which on occasion can be prickly and rejected by grazing animals. 
     Raphanus sativus  with large bulbs may be grown for animal fodder, notably in South Africa. The cultivars used are relatively early flowering and will usually bolt to flower within 3 months of sowing. 
   The nutritive value of fodder radish for animal feed is known to be high and the species possesses some valuable characteristics for livestock farming. However it is clear that there are a number of features of existing cultivars which have limited its ability to provide a flexible source of grazing on farms. 
   The typical radish used for grazing purposes is an annual which bolts to flower very readily and rapidly. This limits its use to a single grazing before flowering as the nutritional value declines considerably at flowering. Later flowering forms would provide more flexibility on farm by allowing farmers to keep the feed until needed. This is very apparent in the related  Brassica  species fodder rape ( Brassica napus ), turnip ( Brassica rapa ) and kale ( Brassica oleracea ) where both annual and biennial forms exist. As a result in these species the biennial forms are more widely used for animal fodder than the annual forms. The delayed flowering of the biennials allows the energy they assimilate to accumulate into storage organs such as bulbs, leaf or stems. From this perspective later flowering or biennial radishes with a long growing period would be valuable for grazing over the summer, or kept until autumn and winter in a nutritious vegetative state. 
   When typical fodder radish crops are grazed by animals the growing point of the plant is above ground and it is damaged, limiting any regrowth. It would be valuable for a plant to have multiple low growing points to avoid grazing damage and allow maximum recovery. 
   The majority of traditional fodder and vegetable radish forms of  Raphanus sativus  are covered in short prickly hairs or trichomes and this feature can render the plant less palatable to livestock than glabrous types.  Raphanus  plants which lack trichomes are preferred by grazing livestock. 
   SUMMARY OF THE INVENTION 
   It is an object of the invention to provide a better fodder radish plant for livestock grazing which can be grazed more than once or to at least provide the public with a useful choice. 
   The invention provides a fodder  Raphanus  plant which can be grazed more than once by livestock. 
   The invention also provides seeds, pollen, ovules and vegetative propagules of the plant. 
   The fodder radish is preferably  Raphanus  species. 
   Within this specification the term  “Raphanus”  is intended to include any radish species including but not limited to  Raphanus sativus, Raphanus maritimus, Raphanus landra  and  Raphanus raphanistrum.    
   The  Raphanus  is preferably very late flowering or biennial in habit which allows grazing over a longer period than more rapidly flowering or annual crops. 
   The  Raphanus  preferably has a low crown to allow recovery from grazing by livestock. 
   The  Raphanus  preferably has multiple growing points to enhance the ability to recover from grazing by livestock. 
   The  Raphanus  preferably has minimal leaf and stem trichomes (or hairs) to enhance the palatability of the plant to grazing livestock. 
   The invention also provides fodder radish which can be multiply grazed and which has at least one of the following characteristics:
         a) palatable and nutritious;   b) able to establish quickly under diverse field conditions;   c) provide a useful amount of fodder into a drought period;   d) tolerant or resistant to common pests, viruses and diseases affecting Brassica crops;   e) persistent over a number of grazing cycles;   f) provide a useful amount of fodder during the winter period;   g) have a yellow seed coat;   h) have minimal anthocyanin expression anywhere on the plant; or   i) recovers to produce a useful amount of herbage.       

   The  Raphanus  species may contain genetic introgression from other species such as  Brassica.    
   The invention provides the plant or its parts producing seed, pollen of the plant, an ovule of the plant and vegetative propagules of the fodder species adapted for multiple grazing. 
   In particular the invention provides a  Raphanus  seed designated PG545. 
   The invention also provides a  Raphanus  plant having all the physiological and morphological characteristics of the  Raphanus  plant derived from the seed of the  Raphanus  PG545. 
   The invention also provides a method for producing a hybrid  Raphanus  seed which seed produces a plant capable of being multiple grazed, comprising crossing a first parent  Raphanus sativus  plant with a second parent  Raphanus  plant and harvesting the resultant hybrid  Raphanus.    
   The invention also provides a hybrid seed produced by the method above. 
   The invention also provides a hybrid plant or its parts produced by growing said hybrid  Raphanus  seed above. 
   The invention also provides vegetative propagules of the fodder  Raphanus  species. 
   The invention also provides a method for the production of  Raphanus  with the ability to regrow after grazing to be suitable for multiple grazing which comprises:
         a) crossing or backcrossing  Raphanus sativus  with  Raphanus maritimus  to produce hybrid plants   b) selecting for low crown and improved recovery from grazing in the progeny over subsequent generations       

   The invention also provides a method of the production of  Raphanus  cultivars with glabrous leaves which comprises:
         a) crossing or backcrossing the common phenotype with trichomes on the leaves of  Raphanus  with  Raphanus  plants containing genes for glabrous leaves to produce hybrid plants   b) selecting for the presence of glabrous leaves in the progeny of subsequent generations       

   The invention also provides a method of the production of  Raphanus  with an extremely late flowering behaviour which comprises:
         a) crossing or backcrossing the common early flowering  Raphanus  with extremely late flowering  Raphanus  plants to produce hybrid plants   b) selecting for late flowering in the progeny of subsequent generations       

   The invention further provides the plant or its parts producing tetraploid seed or pollen for the production of tetraploid seed of the fodder  Raphanus  which can be multiply grazed by livestock. 
   The invention further provides an ovule of the tetraploid plants and vegetative propagules of the tetraploid plants. 
   The invention also provides a tetraploid  Raphanus  plant having all the physiological and morphological characteristics of a  Raphanus  plant derived from the seed of the  Raphanus  which can be multiply grazed by livestock. 
   The invention also provides a method for producing a tetraploid hybrid  Raphanus  seed comprising crossing a tetraploid first parent  Raphanus  plant with a second parent tetraploid  Raphanus  plant and harvesting the resultant hybrid Raphanus seeds, wherein said first or second parent  Raphanus  plant a tetraploid  Raphanus  plant which can be multiply grazed by livestock. 
   The invention also provides a tetraploid hybrid seed produced by any method above. 
   The invention also provides a tetraploid hybrid plant or its parts produced by growing hybrid  Raphanus sativus  seed produced by any method above. 
   The invention also provides vegetative propagules of tetraploid plants. 
   Preferably the fodder  Raphanus  plant is grown from the seed PG545. It may be grown however from any seed having these characteristics such as, for example PG534 and PG560. 
   The invention will now be described by way of example only with reference to the following embodiments. 

   
     BRIEF DESCRIPTION OF THE FIGURES 
     The following Detailed Description, given by way of example, but not intended to limit the invention to specific embodiments described, may be understood in conjunction with the accompanying Figures, incorporated herein by reference, in which: 
       FIG. 1  shows plants of the multiple graze radish in the second summer after sowing, showing the survival alongside winter forage cultivars of rape ( Brassica napus ) and leaf turnip ( Brassica rapa ), both of which had failed to survive into the second summer. 
       FIG. 2  shows a cow grazing multigraze forage radish. 
       FIG. 3  shows a clipped plant of multiple grazing radish showing the many stems developing from a large crown. 
       FIG. 4  shows a single crown of multigraze radish showing the multiple regrowth sites after five grazing cycles. 
       FIGS. 5 and 6  show roots of the multigraze radish showing the branched nature of the root and large crown with many emerging stems. 
       FIG. 7  shows a plant of multiple grazing radish showing the multiple stems developing from a large crown after five grazing cycles. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   As used herein, the terms “comprises”, “comprising”, and the like can have the meaning ascribed to them in U.S. Patent Law and can mean “includes”, “including” and the like. 
   In order to develop a multiple grazing fodder radish it was necessary to obtain a series of parental germplasm lines which contained the range of necessary features, or “phenotypes”. The necessary features were available in 2 different  Raphanus  species: 
   
     
       
             
             
             
           
         
             
                 
             
             
               Feature 
               
                 Raphanus maritimus 
               
               
                 Raphanus sativus 
               
             
             
                 
             
           
           
             
               Very Late flowering 
               + 
               Mostly − few + 
             
             
               Multiple growing points 
               + 
               − 
             
             
               Deep crown 
               + 
               − 
             
             
               Forked root 
               + 
               − 
             
             
               Persistent for 2 years 
               + 
               − 
             
             
               Regrowth from grazing 
               + 
               − 
             
             
               Trichomes (unpalatable hairs) 
               − 
               Mostly − few + 
             
             
               Dehiscent pods 
               − 
               + 
             
             
               Harvestable seed 
               − 
               + 
             
             
                 
             
           
        
       
     
   
     Raphanus maritimus  occurs on the sea coast of Europe and southern England. It has features which are of valuable for multiple grazing purposes such as a very low crown and a deep forked root. It is also very late to flower and may survive up to 2 or more years. It also has useful amounts of salt tolerance. However, it can not be used directly for grazing due to the extreme prickly nature of the trichomes (leaf hairs) on the leaves and stem and the silique or pods are non-dehiscent and do not release the seed and must be sown as pod pieces making it difficult to domesticate the plant for modem agriculture. In order to take advantage of the desirable features it is necessary to first cross this species with domesticated  Raphanus sativus  to combine the useful features into one population. These two species had previously been successfully crossed, indicating that no crossing barrier existed between the species (McNaughton 1976). 
     Raphanus sativus  used for production have dehiscent pods enabling a high seed yield. They are also rapid to establish and many cultivars have a high forage yield for a single grazing. These features are of value for a multiple grazing radish. 
   Within  Raphanus sativus  there is a variation in the number of plant trichomes (hairs on the leaf and stem). Glabrous forms are more palatable to grazing animals and are desirable in a multiple grazing fodder radish. The glabrous form Biser was used as a source of this feature in crosses. This feature of Biser originated as a result of introgression from cabbage ( Brassica oleracea ) (Bonnet 1979). Although this source was used it would be possible to use other glabrous sources of germplasm. 
   Within  Raphanus sativus  there is a large variation for flowering time. Most forms are early flowering but less common late flowering forms requiring a degree of vemalisation also exist. For a multiple grazing fodder radish late flowering forms are desirable and a selection for very late flowering within Long Black Spanish were used as a basis of late flowering in subsequent crosses. Although this source was used it would be possible to use other late flowering sources of germplasm. 
   To obtain all the necessary features of  Raphanus sativus  which are of value for a multiple grazing fodder radish it was necessary to cross 2 populations together and select for the desirable features. The very late flowering selection from Long Black Spanish was crossed with the glabrous line Biser. This gave a late flowering glabrous radish suitable for crossing with  Raphanus maritimus.    
   Further selection over 4 cycles gave a very late flowering glabrous radish. The population resulting from 3 cycles of selection was crossed with  Raphanus maritimus  and selected over 3 cycles for glabrous leaves and late flowering. However, this population still had a proportion of non-dehiscent pods so was crossed back to the 4 th  cycle of selection from the late flowering selection from Black Spanish cross Biser. 
   This population was then selected for all the features required in a multiple grazing radish, including the following:
         Late flowering habit with a long vegetative period   A deep large forked root with a low crown   Multiple growing points   Recovery from grazing over many cycles   Glabrous leaves   A dehiscent pod or silique for ease of seed harvest   High forage yield   The ability to survive for more than 1 year in suitable environments   High disease and pest resistance   Rapid establishment   Yellow seed coat   Low expression of anthocyanin pigment on all parts of the plant       

   This resulted in 3 multiple grazing radish lines PG534, PG545 and PG560. Seed of these are deposited in the Margot Forde Germplasm Centre at AgResearch, Palmerston North, New Zealand. Seed of PG534, PG545 and PG560 were also deposited under the terms of the Budapest Treaty with the Agricultural Research Service Culture Collection (NRRL), 1815 North University St., Peoria, IL. Deposited seed will be irrevocably and without restriction or condition released to the public during the term of any patent issued from this application. 
   The invention has resulted from a series of complex crosses and selection from a range of germplasm sources and species over 16 years, as outlined in the breeding history of Table 1. All crosses were carried out in the field by placing a few plants of one parent among many plants of the other parent. A high selection pressure was maintained with between 1000 and 1 million plants being planted in each generation. Each cycle of selection resulted in 7 to 20 parents, which were allowed to interpollinate together in isolation. 
   The resulting selections have a complex origin incorporating germplasm from three species in the approximate proportions as determined by pedigree;  Raphanus sativus  (86.7%),  Raphanus maritimus  (7.5%) and  Brassica oleracea  (5.8%). 
   Although this Figure outlines the crosses and selections undertaken to develop the multiple grazing fodder radish it would be possible to develop such types using slightly different materials and methods. It would be important to use germplasm lines which contain all the desirable features as outlined above and then cross between them and to select for a combination of these features over many cycles of selection. 
   Whilst the invention has been described with reference to specific embodiments, it will be appreciated that numerous modifications and variations can be made to these embodiments without departing from the scope of the invention as described in this specification and the following claims. 
   The invention is further described by the following numbered paragraphs:
     1. A fodder  Raphanus  plant which can be grazed more than once by livestock.   2. A fodder  Raphanus  plant according to paragraph 1 that is a  Raphanus  species selected from the group  Raphanus sativus, Raphanus maritimus, Raphanus landra  and  Raphanus raphanistrum.      3. A fodder  Raphanus  plant according to paragraph 1 that is very late flowering or biennial in habit which allows grazing over a longer period than more rapidly flowering or annual crops.   4. A fodder  Raphanus  plant according to paragraph 1 that has a low crown to allow recovery from grazing by livestock.   5. A fodder  Raphanus  plant according to paragraph 1 that has multiple growing points to enhance the ability to recover from grazing by livestock.   6. A fodder  Raphanus  plant according to paragraph 1 that has minimal leaf and stem trichomes (or hairs) to enhance the palatability of the plant to grazing livestock.   7. A fodder radish that can be grazed many times and which recovers to produce a useful amount of herbage.   8. A fodder radish that can be multiply grazed and which has at least one of the following characteristics:
       a) palatable and nutritious;   b) able to establish quickly under diverse field conditions;   c) provide a useful amount of fodder into a drought period;   d) tolerant or resistant to common pests, viruses and diseases affecting  Brassica  crops;   e) persistent over a number of grazing cycles;   f) provide a useful amount of fodder during the winter period;   g) have a yellow seed coat;   h) have minimal anthocyanin expression anywhere on the plant;   
       9. A fodder radish according to paragraph 8 that contains genetic introgression from other species such as  Brassica .   10. Seeds, pollen, ovules, vegetative propagules of the fodder  Raphanus  plant according to any one of paragraphs 1-9.   11.  Raphanus  seed designated PG545.   12.  Raphanus  seed having all the physiological and morphological characteristics of the  Raphanus  plant derived from the seed of the  Raphanus  PG545.   13. A method for producing a hybrid  Raphanus  seed which seed produces a plant capable of being multiple grazed, comprising crossing a first parent  Raphanus sativus  plant with a second parent  Raphanus  plant and harvesting the resultant hybrid  Raphanus.      14. Hybrid seed produced by the method of paragraph 13.   15. A hybrid plant or its parts produced by growing hybrid seed of paragraph 14.   16. A method for the production of  Raphanus  with the ability to regrow after grazing to be suitable for multiple grazing which comprises:
       a) crossing or backcrossing  Raphanus sativus  with  Raphanus maritimus  to produce hybrid plants   b) selecting for low crown and improved recovery from grazing in the progeny over subsequent generations   
       17. A method of the production of  Raphanus  cultivars with glabrous leaves which comprises:
       a) crossing or backcrossing the common phenotype with trichomes on the leaves of  Raphanus  with  Raphanus  plants containing genes for glabrous leaves to produce hybrid plants   b) selecting for the presence of glabrous leaves in the progeny of subsequent generations   
       18. A method of the production of  Raphanus  with an extremely late flowering behaviour which comprises:
       a) crossing or backcrossing the common early flowering  Raphanus  with extremely late flowering  Raphanus  plants to produce hybrid plants   b) selecting for late flowering in the progeny of subsequent generations   
       19. A plants or its parts producing tetraploid seed or pollen for the production of tetraploid seed of the fodder  Raphanus  which can be multiply grazed by livestock.   20. An ovule of the tetraploid plants and vegetative propagules of the tetraploid plants of paragraph 19.   21. A tetraploid  Raphanus  plant having all the physiological and morphological characteristics of a  Raphanus  plant derived from the seed of the  Raphanus  which can be multiply grazed by livestock.   22. A method for producing a tetraploid hybrid  Raphanus  seed comprising crossing a tetraploid first parent  Raphanus  plant with a second parent tetraploid  Raphanus  plant and harvesting the resultant hybrid  Raphanus  seeds, wherein said first or second parent  Raphanus  plant a tetraploid  Raphanus  plant which can be multiply grazed by livestock.   23. A tetraploid hybrid seed produced by any method of paragraph 22.   24. A tetraploid hybrid plant or its parts produced by growing hybrid  Raphanus sativus  seed produced by the method of paragraph 22.   25. Vegetative propagules of tetraploid plants according to paragraph 24.   26. A  Raphanus  plant grown from the seed PG545 or any seed having these characteristics such as, for example PG534 and PG560.   

                         TABLE 1               Grazing radish pedigree                                                                                                                         
REFERENCES
     Bonnet A 1979 Inheritance of some characters in radish ( Raphanus sativus ).  Cruciferae Newsletter  4: 31   George R A T, Evans D R 1981 A classification of winter radish cultivars  Euphytica  30: 483-492   Johnston T D 1963 The fodder radish. Welsh Plant breeding Station Annual Report 1963: 135-139   Johnston T D 1977 Breeding aspects of  Raphanus  and  Brassica. Cruciferae Newsletter  2: 13   McNaughton I H 1976 The possibility of leafy, biennial radishes from hybridisation of  Raphanus sativus  (fodder radish) and  R. maritimus  (sea radish).  Cruciferae Newsletter  1: 21-22   Rethman N F G, Heyns G 1987 Grazing of  Raphanus sativus  L (Japanese radish) Journal of the Grassland Society of South Africa 4:154   Verschoor A, Rethman N F G 1992 Forage potential of Japanese radish ( Raphanus sativus ) as influenced by planting date and cultivar choice. Journal of the Grassland Society of South Africa 9:176-177