Fluff Supply

The National Hybridization Garden (NHG) is a facility at Coimbatore established in 1974 as a common platform for sugarcane breeders of different AICRP (All India Coordinated Research Project) centres to directly involve them in parental selection and crossing. It is a common breeding plot, where all the required parental clones as suggested by the concerned centres, well in advance, are planted every year. Necessary support is provided to make the crosses as desired by them. The dried fluff is collected at the end of the flowering season, cleaned and dispatched to the respective centres after the germination test. Annually around 600 parental clones are planted and maintained. The clones which have not been in use for previous three years are excluded from the garden. New parental clones decided by the centres are included after having quarantined. The Elevated Hybridization Runways installed in the field improves the efficiency of the crossing programme by simplifying the pollen collection and dusting operations. The scientists from the participating centres themselves could do the collection of male spikelets, effecting pollinations and collection of matured fluff, with limited assistance from other workers.

In 2011-12, 649 parental clones were maintained of which 507 clones flowered. A total of 552 bi-parental experimental crosses were made for 24 participating centers. Maximum number of crosses were made by North West Zone (206), followed by Peninsular Zone (165), North Central Zone (124) and East Coast Zone (68). Zonal crosses were made for all the zones viz., Peninsular Zone (14), East Coast Zone (11), North West Zone (9), and North Central and North East Zones (15). A poly cross nursery was planted separately for tropical region with 13 female and eight male parents and for subtropical region with eight female and eight male parents. Open pollinated fluff (general collection or GC) from 312 parents was also collected for distribution to participating centres.

Distant Hybridization Garden

To facilitate the participating centres in attempting distant crosses using wild related genera and species as parents, the distant hybridization garden facility was established at Research Centre Agali (Kerala). Every year interested participants are attempting wide crosses and the resultant fluff being despatched after harvesting, cleaning and germination testing

National Impact of fluff supply programme

A number of popular varieties suitable for major States of the country have been bred through the fluff supply programme. A list of such varieties is given below:

List of popular sugarcane varieties developed through fluff supply programme

♥Uttar Pradesh: CoLk 8001, CoLk 8102, CoLk 9110, CoS 245, CoS 510, CoS 611, CoS 633,CoS 687, CoS 718, CoS 767, CoS 802, CoS 7918, CoS 8436, CoS 8439, CoS 87220, CoS 88230, CoS 95222, CoS 95435, CoPant 84211, CoS 95255, CoS 96258, CoS 97264, CoS 96268, CoSe 92423, CoSe 91232.

♥ Bihar:CoP 9206, CoP 9301, CoP 9302

♥ Assam:CoJor 1, CoJor 2

♥ Punjab: CoJ 46, CoJ 64, CoJ 67, CoJ 76, CoJ 77, CoJ 78 CoJ 79, CoJ 81, CoJ 83, CoJ 84, CoJ 85, CoJ 82191, CoJ 82315, CoJ 83536, CoJ 84191, CoJ 84291, CoJ 94192

♥ Haryana: CoH 7801, CoH 7802 ,CoH 7803, CoH 56, CoH 70, CoH 110, CoH 119

♥ Madhya Pradesh: CoJn 861417.

♥ Gujarat:CoN 87263,CoN 91132

♥ Maharashtra:CoM 7125, CoM 88121, CoM 0265

♥ Karnataka:KHS 3298

♥ Andhra Pradesh: CoA 7601, CoA 7602, CoA 7701, CoA 8401, CoA 8402, CoT 8201, CoR 8001, CoR 85096, CoA 88081, CoA 89081, CoA 89082, CoA 89085, CoV 92102

♥ Tamilnadu: CoC 671, CoC 771, CoC 772 , CoC 773, CoC 774, CoC 775, CoC 777, CoC 778, CoC 779, CoC 8001, CoC 8201, CoC 85061, CoC 86062, CoC 90063, Co 91061, CoC 92061, CoG 93076, CoG 94077, CoSi 776, CoSi 86071, CoSi 95071, CoSi 96071

Flowering and seed set in sugarcane are optimum at Coimbatore, which is not the case in other parts of the country. Taking this into consideration a National Hybridisation Garden (NHG) for sugarcane was established at Sugarcane Breeding Institute, Coimbatore in the year 1972 to create a centralized facility for effecting crosses by the sugarcane research stations of the country. There are 23 centres which are actively involved in making crosses for creating variability for further selection in their respective locations. Parental composition of the NHG includes around 500 parents comprising of Co canes, elite clones developed from State Agricultural Universities and IISR Lucknow, Inter Specific Hybrids (ISH), genetic stocks generated for different agronomically important traits and foreign hybrids. Each year around 800 crosses are made by the participating centres in various combinations. A large number of Poly Crosses (PC) is also made every year. Thus NHG serves as a central facility for generating genetic variability in this crop for the entire country for identifying location specific varieties. Conventionally crosses are made following lantern method of crossing at NHG. Female flowers are protected from pollen contamination by enclosing them in a crossing lantern hung from bamboo hoisters (Fig. 1). Reaching the female arrows positioned at 3-6m from ground level for pollination is difficult and possible only by using ladders. Ladders have to be shifted after every pollination and several ladders have to be used simultaneously to complete the targeted crosses within crossing time of 1-2hr (Fig 2). Thus the procedure is cumbersome, labor intensive and time consuming.

In order to improve the efficiency of the crossing programme and to simplyfy the pollen collection and dusting operations, a new robust structure called as Elevated Hybridization Runways (EHR) was conceived and designed by Sugarcane Breeding Institute, Coimbatore in collaboration with Central Institute of Agricultural Engineering, Regional Centre, Coimbatore (Fig 2). The basic structure of elevated hybridization runway consists of two tiers of G.I Plat form. These platforms are supported by H shaped 48 x 2.65mm G.I. pipe frames braced with 27 x 2.65 mm GI pipes. The H shaped GI pipe frames are assembled on top of each other with interlocking arrangement to make the height to 4.5m. Each unit has 42 H shaped GI pipe poles interconnected by cross bracing at an interval of 2.2m. The width of the structure would be 1.0m. The structure is positioned between two rows of plants with the row spacing of 1.2 m. Eleven such units were made to cover an area of 726 m².

To facilitate the crossing of the flowers situated at different heights the platforms are placed in two levels at 2.85 m and 4.5m from the ground. Each unit consists of two equal subunits of 13.2m length, covering a total length of 26.4 m. Since sugarcane parents planted on either sides of the platform can be accessed for crossing, one unit can effectively cover four rows of 13.2 length. The sub units are placed lengthwise and a platform of 1.5 m is fixed between them to connect the two subunits to provide a continuous pathway. Platforms of two adjacent units are also interconnected to enable the scientists to move from one unit to another without getting down every time. A ladder made of M.S pipe enables the scientist to reach the platforms for making crosses. The researcher can move freely from one platform to the other to carry out the crossing work at different heights. The facility is scientist-friendly and highly safe in design.

The EHR was first installed during the crossing season 2007. The sugarcane breeders from 21 participating centres of National fluff supply programme effectively used this facility. Initially 11 units of this structure were erected to cover 88 rows (6m length) of parental clones during 2007 crossing season. In the EHR facility mostly female parents were planted and used for erecting cages. During this season 234 crosses were made utilizing this structure. Once collection of matured fluff is completed the whole structure can be dismantled and stored safely. Since all the parts are made of standard components, the components are interchangeable making the dismantling and assembling operations easier. If well maintained the structure can be used for atleast 20-25 years.

This innovation was found to save labour considerably. With this system the scientist himself can complete most of the crossing operations like collection of male spikelets, effecting pollinations and collection of matured fluff. It was found that a team of one scientist and one labor can complete 35 crosses a day while by the conventional method this would require 6 labourers. The new facility is of great benefit to the National Fluff Supply Programme of All India Coordinated Research Programme on Sugarcane.