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Not AvailableRed rot, wilt and smut are major diseases that seriously affect sugarcane production in India. The increase in climate variability and drastic change in climate patterns have great impact on occurrence of diseases and in sugarcane, resistance breeding is the only solution to tackle this problem. In an attempt to increase diversity of wild germplasm through introgression in base broadening programmes, variability within Saccharum species was assessed to identify different sources of resistance to red rot and smut for use in breeding programmes to identify resistant cultivars. The 136 BC1 hybrids from two crosses of improved S.officinarum x improved S. robustum and 100 BC2 clones involving BC 1× Co 86011, Co 09014 were evaluated for red rot ( cf 671 by CCT ) and assessed for natural incidence of smut during 2016 and 2017 seasons. Out of 100 BC1 hybrids with improved S.officinarum as recurrent parent, 62 clones ( 45.58 percent ) had no natural incidence of smut and 32 clones ( 23.52 percent ) showed MR or R reaction to red rot. Of the 80 tested BC2 lines involving commercials as a backcross parent, 18 ( 22.5 percent ) were resistant to moderately resistant to red rot and 31 clones (38.75 %) were free from smut incidence. BC1 progenies had more resistant types than BC 2. Eleven clones from this group viz.,12-15,12-44,13-36,13-44,13-69,13-251,14-48,14-14,14-144,14-125,14-102 combined resistance to red rot and with no natural smut incidence in trials. Along with resistance these clones combined yield and sucrose percent at 360 days. About 11.2 percent of the BC1 progenies of ( Co 8371 x S.barberi ( Pathri ) x Co 0209 ) were moderately resistant to red rot and clones 13-176 and 14-60 combined sucrose, red rot resistance and yield. The F1 progenies ( 281 ) involving improved S. spontaneum had 27.78 percent produced predominantly resistant progenies involving 96-38,96-195,97-12, 96-319, 96-137, 96-77 as donors. The study suggests that resistant hybrids involving improved S. robustum and S. barberi germplasm could also be used as source of smut and red rot resistance in sugarcane breeding programs apart from S. spontaneum. The new genetic stocks identified with multiple disease resistance and other desirable traits are to be exploited by the breeders to combat the future climate challenges to identify clones with stable resistance.Not Availabl

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Not AvailableSugarcane breeding has been a success all over the world by intercrossing the original interspecific hybrids but a very few Saccharum species clones have been exploited in the breeding programme. The exploitation of the unutilized clones of cultivated and wild species of Saccharum in breeding program was suggested as early in 1960’s (Berding & Roach, 1987) who indicated that the repeated use of few parents in hybridization have resulted in narrow genetic diversity in modern sugarcane cultivars. Currently sugarcane cultivars under cultivation have a narrow genetic base tracing back less than 20 S.officinarum, two S.spontaneum and a couple of S. barberi and S.sinense clones which offers a major threat to the sugarcane productivity and demands concerted efforts to utilize new germplasm. Pre-breeding aims at creating new base population by gene introgression that enhances genetic variability in the germplasm for direct use in breeding programmes. It can also assist in identifying heterotic patterns for hybrid programs. Backcrossing is an efficient way to transfer characteristics controlled by one or two genes, although it can be used also for higher number of genes, including quantitative characters. Eberhart (1971) suggested that the first backcross to adapted germplasm is the best base population to start selection. In our study, elite improved clones of S.officinarum and S.robustum produced through intra population improvement programme at ICAR-Sugarcane Breeding Institute (Nair et al..,SBI Annual Report 1991-1996) and commercials were utilized in introgression through backcross breeding. The back cross generations and nobilized hybrids (F1 BC1, BC2) were explored for their heterotic pattern and breeding potential. Selection during nobilisation :The prebred clones developed (utilizing improved S. officinarum, improved S. robustum and commercial Co canes), from three nobilized generations and different mating groups exhibited extensive variability for both qualitative and quantitative traits.They expressed wide variability for various traits like cane population, cane height, cane diameter, canopy colour, internode shape, internode color, spines and flowering. Significant variation was recorded for cane growth and yield characters.The means for the F1, BC1,BC2 generations showed progressive increase of yield traits and sucrose % with successive stages of nobilisation. Heritability estimates varied over the different nobilising generations. Heritability estimates from this study, indicate that selection of parents for sucrose % during the nobilisation process will be effective. The results indicate that gain from selection for yield traits like number of millable canes and single cane weight at the BC1 and BC2 stages was moderate to high. In general, sucrose % have shown moderate to moderately high heritability and clump yield of low to moderate heritability. Genetic improvement in the backcross generations: In the improved S.robustum x improved S.officinarum group, the first generation nobilized hybrids showed an improvement of 15.12% for sucrose % at 360 days over the improved S.officinarum parents. BC1 hybrids showed an improvement of 16.71% and 34.09 % for sucrose % at 360 days in comparison with improved S.officinarum and S. robustum parents respectively. BC2 hybrids showed an improvement of 22.36% and 40.58 % for sucrose % at 360 days in comparison with improved S.officinarum and S. robustum parents respectively. Number of millable canes, cane height and single cane weight exhibited a substantial improvement compared to their improved S.robustum S. officinarum parents. BC1 and BC2 exhibited improvement for both yield and quality parameters suggesting further exploitation. The hybrids from the improved S.officinarum x improved S. robustum group also exhibited improvement for both yield and quality traits. There was an improvement of 23.57 % for sucrose in F1, 30.37 % in BC1 and 33.35 % in BC2 in comparison with improved S.officinarum parents. Similarily an improvement of 41.97 %, 49.78 % and 53.21 % was observed in F1, BC1 and BC2 respectively in comparison with improved S. robustum parents. The BC3 hybrids from these two mating groups also exhibited improvement for yield and quality traits suggesting further studies on cytogenetical behaviour and breeding potential in further backcross generations. Breeding potential of pre-bred clones From the study, the crosses PIR 001157 x PIO 00845, PIO 001057 x PIR 00 1062, PIR 03-107 x PIO 96-475, PIO 94-345 x PIR 96-258, PIR03-107 x PIR 96-475 ,PIO 001100 x PIR 001174 gave more selections that combined yield and quality traits. Crosses with PIR 96-285, PIR 001188, 99 -269 as one of the parents were identified as potential with high quality recombinants. Significant variation was recorded for growth and yield characters in the prebreeding population. Among the prebred materials, 26 clones recorded single cane weight > 1.25 kg, 45 clones with brix % above 20 % and 41 clones with juice sucrose above 18.5 % and most of them were derived from the crosses involving improved S.officinarum x Improved S.robustum.The clones viz., 13-36,13-38,13-39,13-44,13-78,13-80,13-125,13-150,13-151,13-198,13-272,13-266 and 13-250 with good field stand, yield and quality parameters comparable with Co 86032 were identified as genetic stocks for further utilization. The clones 13-69,13-103 and 13-251 showed substantial improvement for sucrose % at 360 days. The clone 13-147 recorded the maximum single cane weight of 1.45 kg.The pre-bred clones were tested for tolerance to water deficit conditions, red rot and for natural incidence of smut. The clones involving PIR 001057, PIR 001058, PIR 96-285, PIR 00 1022 as parents in the back crosses were moderately resistant and moderately susceptible to red rot. The promising clones did not show natural incidence of smut. Under water defcit conditions, 25 clones exhibited good growth and response, coupled high yield (95-98.0t/ha) and sucrose (19.85 -20.94%) indicating their ability of adaptation under changing climate. IOR 360 showed significant improvement for cane yield (21.05%) and sucrose (10.14 %) followed by IOR 396, 258, 1100, 1136 and 1128. These clones also combined resistance to red rot. Earlier studies have indicated that clones with S. robustum cytoplasm performed better at high temperature and water deficit conditions and hence the pre-bred clones with genetic base of S. robustum might prove as a potential donor for tolerance to high temperature. Forty prebreeding clones were selected based on genetic diversity and were screened for molecular diversity using sugarcane specific markers. Variation in allelic size was detected within the range of 122-1136 bp and maximum of up 33 alleles. Among the SSR primers used, NKS 34142 & 185 were specific to PIR 00 1057, marker NKS 8181, 312 & 336 were specific to PIR 00 1057, Maximum molecular diversity was detected in the crosses involving PIR 00-1174, PIR 00-1163, PIR 001057 as female parents indicating the use of these clones as diverse parents in hybridization. Though introgression of wild germplasm is time consuming and requires considerable efforts and resources, it is very important to improve the commercial breeding populations. Pre-breeding strategy in our study through back crossing has helped in identifying clones combining yield, quality and resistance to red rot and smut. Utilization of these clones by the breeders will help in the development of new breeding populations to work upon and on identifying clones to improve resistance to red rot, smut and tolerance to drought and salinity stressesNot Availabl

Castor Management Practices

Not AvailableCastor management practices explained in teluguNot Availabl

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Not AvailableSugarcane is a commercial crop that is cultivated across the globe for its sucrose. It is now recognized as an important energy crop which effectively utilizes solar energy and converts into chemical energy for biofuel production. Sugarcane as a bio feedstock contributes 40 % towards biofuel production worldwide and classified as the most favourable crop in terms of energy input and output ratio. Energy cane and commercial cultivars are generally derived from interspecific hybridization between Saccharum officinarum and S. spontaneum. S. spontaneum has contributed important traits to cultivars such as adaptation to environmental stress, diseases resistance and ratooning ability and recently it has gained importance for the improvement of wide adaptability, energy generation from biomass and high fibre. The genetic base broadening programme in Sugarcane Breeding Institute, Coimbatore involved the utilization of improved germplasm of S.officinarum and S.spontaneumin breeding programmes to identify clones with multipurpose utility which resulted in new gene pool of diversity and identification of genetic stocks for red rot resistance, yield, fibre, biomass and good juice quality. Even though this base broadening programme was to introgress important yield and quality traits, it also formed a source of clones with high biomass production and high fibre %.In this study, progenies from twenty three biparental crosses involving commercial sugarcane clones, improved S.officinarum and improved S. spontaneum clones along with parents were evaluated for cane population, tillering ability, cane height, cane diameter, total sugars,pol % juice, CCS %, total biomass and fibre %. Statistically significant differences and high genetic variation was observed among the families and clones. Coefficient of variation was high for the attributes and it ranged from 18.83 % for fibre % to 44.80 % for cane yield. The F1clones exhibited high vigour with high cane population, tall and erect canes. Intensity of flowering was also high in these clones. The highest yield of fresh weight and dry matter biomass was obtained in first generation of improved spontaneum hybrid derivatives. Among the traits studied, cane length ranged from 185 -285 cm , fibre % (13.92 -22.05%), total dry biomass(5.92 to .35.01 kg/row), number of millable canes ( 42-98.24), total sugars ( 16.45 - 23.15 %) ,pol % juice (12.18 - 21.49 % ) and juice purity ( 78.62 – 92.86%). Among the crosses studied, eleven crosses were promising with number of millable canes above 91 / row of 3ft length, cane length of 285 cm, and Brix % of 23.15 %. The highest yield of dry matter and total biomass and fibre % was observed in the cross PIO 88- 96 x IND 82-319. CoC 671 x PIS 38 , PIO 88-1715 x IND 82-319 recorded highest brix % and pol % juice.PIO 88-96 x IND 82-319 ,PIO 88-96 x IND 82-319,PIO 88-104 x IND 82-319 were promising for millable canes, cane length and single cane weight. Moderate to high (0.41 to 0.78) heritability and high genetic variances were observed for all the traits. Moderate heritability was observed for fibre % and highest for single cane weight and total dry biomass. Correlation studies indicated that number of millable canes was positively correlated with fibre %. Moderate correlation was observed for CCS % and cane yield.NMC had positive correlation with cane yield, fibre % and CCS t/ha. All the traits except cane length had positive correlation with fibre %. Cane length, cane diameter and stalk weight had positive correlation with total dry biomass. Correlation studies within families also indicated both positive and negative correlations among the traits. The positive correlations of the yield traits with fibre % and total dry biomass indicates that direct selection for cane length, cane diameter and single cane weight will improve fibre % and total dry biomass. The genetic variability for the biomass traits and fibre % observed in this study indicates that selection of high biomass energycane families and clones at early generation will be advantageous and basic information on selection indices for these biomass traits has to be worked out for effective identification of biomass potential clones in our breeding programmes. The spontaneum parents viz., PIS 54, IND 82-319, PIS 18, and PIS 93-24 utilized in this study combine red rot resistance, erectness, vigour, moderate quality and can be further exploited in advanced breeding programmes to identify high biomass types. Seventy three elite potential recombinants identified from this study were further classified into two groups’ viz., high fibre with moderate total sugars and moderate fibre with high total sugar clones which forms a new energy source for energy and ethanol production. These clones showed moderate flowering and warrants large scale evaluation in multilocations which will be useful in identifying high biomass, well adaptable energy canes for the future.Not Availabl