Search

'CP 10‐1620' (Reg. no. CV‐216, PI 693837) sugarcane (a complex hybrid of Saccharum spp.) was developed through cooperative research conducted by the USDA–ARS, the University of Florida, and the Florida Sugar Cane League, Inc. At the June 7, 2018, Florida Sugarcane Variety Committee Meeting, CP 10‐1620 was released to growers for mineral (sand) soils in Florida, and seed was available in September 2018. CP 10‐1620 was selected from a polycross of 'CP 00‐1100' × 'CP 05‐1740' (Cross no. X07‐1225) made at Canal Point, FL, in December 2007. Neither the female parent, CP 00‐1100, nor the male parent, CP 05‐1740, is a commercial cultivar. Cane yield of CP 10‐1620 on sand soils, averaged across 12 harvests through three crop cycles (plant cane, first ratoon, and second ratoon), was 11.0% higher (P < 0.05) than the combined mean of three checks, 'CL 88‐4730', 'CP 96‐1252', and 'CPCL 97‐2730', which are commercial checks for sand soils. The commercial recoverable sucrose for CP 10‐1620 was not significantly lower than the combined mean of the checks but the higher cane yield resulted in 8.4% higher (P < 0.05) sucrose yield than the combined mean of the checks. CP 10‐1620 was released because of its high cane yields on sand soils, and its acceptable levels of resistance to brown rust (caused by Puccinia melanocephala H. & P. Sydow), leaf scald (caused by Xanthomonas albilineans Ashby, Dowson), Sugarcane mosaic virus strain E (mosaic), smut (caused by Sporisorium scitamineum), Sugarcane yellow leaf virus, and ratoon stunt [caused by Leifsonia xyli subsp. xyli (Davis et al.) Evtushenko]. CP 10‐1620 was moderately susceptible to orange rust (caused by Puccinia kuehnii E. J. Butler), and it has high freeze tolerance. CP 10‐1620 tested positive for the Bru1 locus, which is an indicator of brown rust resistance. Core Ideas: CP 10‐1620 is a new sugarcane cultivar in Florida.CP 10‐1620 has high yields of cane and sucrose in Florida.CP 10‐1620 is resistant or moderately resistant to the typical diseases found in Florida.CP 10‐1620 is the result of a cooperative effort between the USDA, UF IFAS, and the Florida Sugar Cane League.CP 10‐1620 has high cold tolerance. [ABSTRACT FROM AUTHOR]

'CP 13‐1954' (Reg. no. CV‐218, PI 704104) sugarcane (Saccharum spp. hybrid) was developed through cooperative research conducted by the USDA–ARS, the University of Florida, and the Florida Sugar Cane League, Inc., and released to growers for organic (muck) soils in Florida in June 2020. The parentage of CP 13‐1954 is 'CP 85‐1491' × Poly 09‐24. Based on the results of three crops (plant cane, first ratoon, and second ratoon) in field trials conducted at five locations, CP 13‐1954 had higher cane yield (16.2%), sucrose yield (15.6%), and economic index (29.7%) at P <.05 compared with the reference cultivar, 'CP 96‐1252'. CP 13‐1954 stalks are usually taller than the reference cultivar, 'CP 00‐1101', with small‐to‐medium diameter, and exhibits resistance to ratoon stunting disease, Sugarcane mosaic virus strain E, brown rust, orange rust, and smut and moderate resistance to leaf scald on muck soils in Florida. CP 13‐1954 has Bru1 locus that provides resistance against brown rust. CP 13‐1954 showed moderate cold tolerance among all the tested cultivars. Core Ideas: CP 13‐1954 is a new sugarcane cultivar released for organic soils in Florida.CP 13‐1954 yields higher than commercial checks in organic soils in Florida.CP 13‐1954 is resistant to most of the common sugarcane diseases in Florida.CP 13‐1954 has moderate level of freeze tolerance. [ABSTRACT FROM AUTHOR]

The sugarcane ratooning ability (RA) is the most important target trait for breeders seeking to enhance the profitability of sugarcane production by reducing the planting cost. Understanding the genetics governing the RA could help breeders by identifying molecular markers that could be used for genomics-assisted breeding (GAB). A replicated field trial was conducted for three crop cycles (plant cane, first ratoon, and second ratoon) using 432 sugarcane clones and used for conducting genome-wide association and genomic prediction of five sugar and yield component traits of the RA. The RA traits for economic index (EI), stalk population (SP), stalk weight (SW), tonns of cane per hectare (TCH), and tonns of sucrose per hectare (TSH) were estimated from the yield and sugar data. A total of six putative quantitative trait loci and eight nonredundant single-nucleotide polymorphism (SNP) markers were associated with all five tested RA traits and appear to be unique. Seven putative candidate genes were colocated with significant SNPs associated with the five RA traits. The genomic prediction accuracies for those tested traits were moderate and ranged from 0.21 to 0.36. However, the models fitting fixed effects for the most significant associated markers for each respective trait did not give any advantages over the standard models without fixed effects. As a result of this study, more robust markers could be used in the future for clone selection in sugarcane, potentially helping resolve the genetic control of the RA in sugarcane. [ABSTRACT FROM AUTHOR]

Genomic selection (GS) has been demonstrated to enhance the selection process in breeding programs. The objectives of this study were to experimentally evaluate different GS methods in sugarcane hybrids and to determine the prospect of GS in future breeding approaches. Using sugar and yield-related trait data from 432 sugarcane clones and 10,435 single nucleotide polymorphisms (SNPs), a study was conducted using seven different GS models. While fivefold cross-validated prediction accuracy differed by trait and by crop cycle, there were only small differences in prediction accuracy among the different models. Prediction accuracy was on average 0.20 across all traits and crop cycles for all tested models. Utilizing a trait-assisted GS model, we could effectively predict the fivefold cross-validated genomic estimated breeding value of ratoon crops using both SNPs and trait values from the plant cane crop. We found that the plateau of prediction accuracy could be achieved with 4000 to 5000 SNPs. Prediction accuracy did not decline with decreasing size of the training population until it was reduced below 60% (259) to 80% (346) of the original number of clones. Our findings suggest that GS is possibly a new direction for improving sugar and yield-related traits in sugarcane. [ABSTRACT FROM AUTHOR]

Breeding for decreased fruit cracking incidence and increased fruit firmness in sweet cherry creates an attractive alternative to variable results from cultural management practices. DNA-informed breeding increases its efficiency, yet upstream research is needed to identify the genomic regions associated with the trait variation of a breeding-relevant magnitude, as well as to identify the parental sources of favorable alleles. The objectives of this research were to identify the quantitative trait loci (QTLs) associated with fruit cracking incidence and firmness, estimate the effects of single nucleotide polymorphism (SNP) haplotypes at the detected QTLs, and identify the ancestral source(s) of functional haplotypes. Fruit cracking incidence and firmness were evaluated for multiple years on 259 unselected seedlings representing 22 important breeding parents. Phenotypic data, in conjunction with genome-wide genotypic data from the RosBREED cherry 6K SNP array, were used in the QTL analysis performed via Pedigree-Based Analysis using the FlexQTL™ software, supplemented by a Genome-Wide Association Study using the BLINK software. Haplotype analysis was conducted on the QTLs to identify the functional SNP haplotypes and estimate their phenotypic effects, and the haplotypes were tracked through the pedigree. Four QTLs (two per trait) were consistent across the years and/or both analysis methods and validated the previously reported QTLs. qCrack-LG1.1m (the label given to a consistent QTL for cracking incidence on chromosome 1) explained 2–15.1% of the phenotypic variance, while qCrack-LG5.1m, qFirm-LG1.2m, and qFirm-LG3.2m explained 7.6–13.8, 8.8–21.8, and 1.7–10.1% of the phenotypic variance, respectively. At each QTL, at least two SNP haplotypes had significant effects and were considered putative functional SNP haplotypes. Putative low-cracking SNP haplotypes were tracked to an unnamed parent of 'Emperor Francis' and 'Schmidt' and unnamed parents of 'Napoleon' and 'Hedelfingen,' among others, and putative high-firmness haplotypes were tracked to an unnamed parent of 'Emperor Francis' and 'Schmidt,' an unnamed grandparent of 'Black Republican,' 'Rube,' and an unknown parent of 'Napoleon.' These four stable QTLs can now be targeted for DNA test development, with the goal of translating information discovered here into usable tools to aid in breeding decisions. [ABSTRACT FROM AUTHOR]

'CP 13‐4100' (Reg. no. CV‐202, PI 698546) sugarcane cultivar (a complex hybrid of Saccharum spp.) was developed through cooperative research conducted by the USDA‐ARS, the University of Florida, and the Florida Sugar Cane League, Inc. The Florida Sugarcane Variety Committee (FSVC) released CP 13‐4100 in June 2020 to growers for commercial cultivation on mineral (sand) soils. It originated from a polycross made at Canal Point (CP) on 3 Dec. 2008 where CP 96‐1252 was the female parent and the male parent was unknown and could be any one of genotypes used in the polycross. CP 13‐4100 was released by FSVC for its high cane and sucrose yields, acceptable commercial recoverable sucrose, and resistances to orange rust, leaf scald, Sugarcane mosaic virus strain E (mosaic), and smut, and acceptable levels of susceptibility to brown rust. CP 13‐4100 and commercial reference checks (i.e., CL 88‐4730, CP 96‐1252, CPCL 97‐2730) yield data were collected from 12 harvests (i.e. three crop cycles—plant cane, first, and second ratoon—at four sand‐soil locations) in final‐stage replicated yield trials. Compared with CL 88‐4730 and CPCL 97‐2730, CP 13‐4100 had significantly (P ≤.0001) higher cane yield (tonnes of cane per hectare: 18.7 and 29.5%), sucrose yield (tonnes of sugar per hectare: 26.3 and 30.7%), and economic index (EI; 10.9–16.9%) and no significant differences from CP 96‐1252 in these traits. CP 13‐4100 tested negative for the Bru1 marker, which is linked to a quantitative major locus of brown rust resistance. CP 13‐4100 could be considered moderately tolerant to freezing among 23 tested genotypes. [ABSTRACT FROM AUTHOR]

'CP 13‐1223' (Reg. no. CV‐204, PI 698176) sugarcane (a complex hybrid of Saccharum spp.) was released to growers in June 2020 for producing on muck soils in Florida. It was developed through a decade‐long cooperative research program between the USDA‐ARS, the University of Florida Everglades Research and Education Center, and the Florida Sugar Cane League, Inc. This cultivar resulted from a poly‐cross made at the USDA‐ARS Canal Point (CP) Sugarcane Field Station. CP 13‐1223 was released because of its high commercial recoverable sucrose (CRS) and stalk weight, and demonstrated acceptable levels of cane and sucrose yields on muck soils. CP 13‐1223 has resistance to orange rust, leaf scald, Sugarcane mosaic virus strain E, ratoon stunt disease, and smut, and moderate resistance to brown rust. Based on results from 13 harvests across replicated yield trials at five locations, CP 13‐1223 performed 29.6 and 9.5% higher in CRS and stalk weight, respectively, than the check cultivar 'CP 96‐1252'. It did not differ significantly from CP 96‐1252 in either cane yield, sucrose yield, or economic profitability. CP 13‐1223 is considered to have moderate tolerance to freezing in field tests. [ABSTRACT FROM AUTHOR]

'CP 12‐1753' (Reg. no. CV‐203, PI 698657) sugarcane (complex hybrid of Saccharum spp.) cultivar was developed through a cooperative research between USDA‐ARS, the Florida Sugar Cane League, Inc., and the University of Florida. It was derived from a polycross made at Canal Point, FL, on 8 Dec. 2010 between a female parent CP 08‐2409 and several male parents. CP 12‐1753 had 11 harvests in Stage 4: plant cane and first ratoon at four locations and second ratoon at three locations. Harvest data showed that CP 12‐1753 had significantly (P ≤.05) higher cane yield and economic index than the reference cultivars 'CL 88‐4730' and 'CPCL 97‐2730', respectively, but had significantly lower cane yield in plant cane and lower economic index than the reference cultivar 'CP 96‐1252'. Freeze tolerance of CP 12‐1753 was lower than the reference cultivars. CP 12‐1753 possesses Bru1, a major gene for brown rust resistance, and showed resistance to brown rust. At the time of release, it was resistant to orange rust, mosaic, and smut. It was moderately resistant to leaf scald and ratoon stunting disease. Considering the agronomic, yield, and disease traits, CP 12‐1753 was released by the Florida Sugarcane Variety Committee in June 2020 to growers for commercial use on mineral (sand) soils. Core Ideas: Sugarcane cultivar CP 12‐1753 was released for Florida mineral soil.CP 12‐1753 has comparable yield to the reference cultivars.CP 12‐1753 has comparable or better disease resistance than the reference cultivars. [ABSTRACT FROM AUTHOR]

Brown rust (caused by Puccinia melanocephala H. & P. Sydow) is one of the most devastating diseases in commercial sugarcane production. It could reduce sugarcane yield by up to 50% depending on the susceptibility levels of cultivars. Breeding disease‐resistant cultivars is the most effective, economical, and environmentally friendly option to control brown rust. A genome‐wide association study was conducted on a field trial using 432 sugarcane clones following an augmented design with two replications. Brown rust was screened using the whorl inoculation method over two crop cycles. The genotype data were obtained through target enrichment sequencing technologies. The gene actions considering six different models and marker dosage effects were included during the marker‐trait analysis. A total of seven, nine, and seven nonredundant marker‐trait associations were identified for plant cane, first ratoon, and across two crop cycles, respectively. The most significant (p‐value 6.17E−20) marker (chr01p59833543) has the additive effect of −0.63 for the diplo‐additive model and reduced disease severity the most (41.35%) due to heterozygote (AG) over homozygote allele (AA) combination in the tested clones. Gene annotation of the monoploid sugarcane genome R570 suggested that six putative candidate genes were co‐located with significant markers associated with brown rust resistance in sugarcane. The putative candidate genes regulated the formation of a cell wall barrier that plays a crucial role in controlling brown rust pathogen infection. The results of this study will open the path to exploiting new resistance sources for brown rust resistance in commercial sugarcane. [ABSTRACT FROM AUTHOR]

Summary: The experiment was carried out in three crop cycles as plant cane, first ratoon, and second ratoon at five locations on Florida muck soils (histosols) to evaluate the genotypes, test locations, and identify the superior and stable sugarcane genotypes. There were 13 sugarcane genotypes along with three commercial cultivars as checks included in this study. Five locations were considered as environments to analyze genotype-by-environment interaction (GEI) in 13 genotypes in three crop cycles. The sugarcane genotypes were planted in a randomized complete block design with six replications at each location. Performance was measured by the traits of sucrose yield tons per hectare (SY) and commercial recoverable sugar (CRS) in kilograms of sugar per ton of cane. The data were subjected to genotype main effects and genotype × environment interaction (GGE) analyses. The results showed significant effects for genotype (G), locations (E), and G × E (genotype × environment interaction) with respect to both traits. The GGE biplot analysis showed that the sugarcane genotype CP 12-1417 was high yielding and stable in terms of sucrose yield. The most discriminating and non-representative locations were Knight Farm (KN) for both SY and CRS. For sucrose yield only, the most discriminating and non-representative locations were Knight Farm (KN), Duda and Sons, Inc. USSC, Area 5 (A5), and Okeelanta (OK). [ABSTRACT FROM AUTHOR]

'CP 11‐1314' (Reg. no. CV‐196, PI 693071) sugarcane, a complex hybrid of Saccharum spp., was developed through cooperative research conducted by the USDA‐ARS, the University of Florida, and the Florida Sugar Cane League, Inc.; it was released to Florida growers in June 2018 for cultivation on organic soils and further recommended in June 2019 for sand soils. This cultivar was derived from a polycross between CP 05‐1451 and a mixture of potential pollen donors. CP 11‐1314 was selected for release based on high cane yield and acceptable sucrose content. In addition, CP 11‐1314 displays good ratooning ability (particularly on muck soils), minimal sucrose decrease following freezing temperatures, and overall disease resistance. CP 11‐1314 is positive for the Bru1 locus, which confers resistance to brown rust, and is resistant or moderately resistant to all other sugarcane diseases of concern in Florida, including ratoon stunt disease, leaf scald, mosaic, and orange rust. [ABSTRACT FROM AUTHOR]

'CP 10‐1716' (Reg. no. CV‐195, PI 691536) sugarcane (a complex hybrid of Saccharum spp.) was released (7 June 2018) through cooperative research by the USDA–ARS Sugarcane Field Station at Canal Point, the University of Florida, and the Florida Sugar Cane League, Inc. CP 10‐1716 is recommended for use on mineral (sand) soils in Florida. CP 10‐1716 resulted from polycross X07‐1257 (CP 00‐2180 × Mix07Q; male parent is unknown). Replicated trials at four sand soil locations, with yield data from 12 harvests and three crop cycles (i.e., plant cane, first ratoon, and second ratoon) showed that CP 10‐1716 had cane and sugar yields, and profitability (economic index, US$ ha−1), that were similar to check cultivars ('CL 88‐4730' and 'CP 96‐1252'). Commercial recoverable sucrose (CRS) in CP 10‐1716 was significantly lower than the check averages, but the early CRS was not significantly different from the mean of the checks. The economic index for CP 10‐1716 vs. the mean of the checks was $2490 vs. $2445 ha−1, respectively, with CP 10‐1716 showing no significant difference from the mean of the checks. CP 10‐1716 was rated as moderately resistant to ratoon stunt disease and resistant to brown and orange rust, mosaic, smut, leaf scald, and yellow leaf disease on sand soils. CP 10‐1716 is positive for the Bru1 molecular marker that is one of the indicators for brown rust resistance. CP 10‐1716 has low to moderate freeze tolerance as it relates to sucrose degradation. [ABSTRACT FROM AUTHOR]

Brown rust, caused by Puccinia melanocephala, is an important disease of sugarcane worldwide. Molecular markers for a major brown rust resistance gene, Bru1, were used to screen a total of 1,282 clones in the World Collection of Sugarcane and Related Grasses ( WCSRG) to determine the distribution and frequency of the gene in Saccharum species and related genera. Bru1 was found across all species within the Saccharum complex, but the frequency varied among species. Bru1 was more prevalent in S. robustum clones (59.1%), whereas it occurred in low frequency and exhibited the highest level of variability as determined by the presence of one or both markers (18.8%) in clones of S. spontaneum. Bru1 frequency was highest in the two secondary cultivated species, S. barberi (79.3%) and S. sinense (71.8%). The frequency of Bru1 was 26.4% and 21.0% in S. officinarum and interspecific hybrid clones, respectively. Knowledge of the distribution and frequency of Bru1 in the WCSRG will complement efforts to characterize diversity in the Saccharum complex for the expected expanded use of marker-assisted selection in the future. [ABSTRACT FROM AUTHOR]

Verticillium wilt, caused by the soilborne fungus, Verticillium alfalfae, is one of the most serious diseases of alfalfa (Medicago sativa L.) worldwide. To identify loci associated with resistance to Verticillium wilt, a bulk segregant analysis was conducted in susceptible or resistant pools constructed from 13 synthetic alfalfa populations, followed by association mapping in two F1 populations consisted of 352 individuals. Simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers were used for genotyping. Phenotyping was done by manual inoculation of the pathogen to replicated cloned plants of each individual and disease severity was scored using a standard scale. Marker-trait association was analyzed by TASSEL. Seventeen SNP markers significantly associated with Verticillium wilt resistance were identified and they were located on chromosomes 1, 2, 4, 7 and 8. SNP markers identified on chromosomes 2, 4 and 7 co-locate with regions of Verticillium wilt resistance loci reported in M. truncatula. Additional markers identified on chromosomes 1 and 8 located the regions where no Verticillium resistance locus has been reported. This study highlights the value of SNP genotyping by high resolution melting to identify the disease resistance loci in tetraploid alfalfa. With further validation, the markers identified in this study could be used for improving resistance to Verticillium wilt in alfalfa breeding programs. [ABSTRACT FROM AUTHOR]

Background: Pokkah boeng disease caused by the Fusarium species complex results in significant yield losses in sugarcane. Thus, the rapid and accurate detection and identification of the pathogen is urgently required to manage and prevent the spreading of sugarcane pokkah boeng. Methods: A total of 101 isolates were recovered from the pokkah boeng samples collected from five major sugarcane production areas in China throughout 2012 and 2013. The causal pathogen was identified by morphological observation, pathogenicity test, and phylogenetic analysis based on the fungus-conserved rDNA-ITS. Species-specific TaqMan real-time PCR and conventional PCR methods were developed for rapid and accurate detection of the causal agent of sugarcane pokkah boeng. The specificity and sensitivity of PCR assay were also evaluated on a total of 84 isolates of Fusarium from China and several isolates from other fungal pathogens of Sporisorium scitamineum and Phoma sp. and sugarcane endophyte of Acremonium sp. Result: Two Fusarium species (F. verticillioides and F. proliferatum) that caused sugarcane pokahh boeng were identified by morphological observation, pathogenicity test, and phylogenetic analysis. Species-specific TaqMan PCR and conventional PCR were designed and optimized to target their rDNA-ITS regions. The sensitivity of the TaqMan PCR was approximately 10 pg of fungal DNA input, which was 1,000-fold over conventional PCR, and successfully detected pokkah boeng in the field-grown sugarcane. Conclusions/Significance: This study was the first to identify two species, F. verticillioides and F. proliferatum, that were causal pathogens of sugarcane pokkah boeng in China. It also described the development of a species-specific PCR assay to detect and confirm these pathogens in sugarcane plants from mainland China. This method will be very useful for a broad range of research endeavors as well as the regulatory response and management of sugarcane pokkah boeng. [ABSTRACT FROM AUTHOR]

Sugarcane (Saccharum spp.) is grown in muck and sand soils in Florida, which comprise of 78 and 22% of the hectarage, respectively. Field studies were conducted from 2004 to 2006 on muck and sand soils for one plant and two ratoon sugarcane crops in a cooperative genotype selection program based at Canal Point, Florida. The studies were conducted to determine the effects of muck and sand soils on the performance of sugarcane genotypes in the final stage (Stage IV) of testing in the breeding program in Florida. Data from six sets of 16 genotypes each from primarily the CP 04-, 05-, and 06- series and CPCL 95-, 02-, 05-, and 06- series in six trial locations on muck soils and three locations on sand soils were collected for three crop years (plant cane, first, and second ratoon). Analyses of mean squares on each soil separately, and for both soils combined, indicated that crop (plant cane, first, and second ratoon) made the highest contribution to the total mean squares. Crop x location was the interaction that made the most contribution to total mean squares. Tons of cane per hectare and tons of sugar per hectare showed crop x location interaction values of 2.95 and 4.38% on muck soils and 19.69 and 15.04% of the total mean squares on sand soils, respectively, which were higher than the other interaction components. Stability analyses indicated that only one genotype was stable for all characters in 2004 and 2005 on muck soils, while one each in 2005 and 2006 on sand soils. Similarly, only two genotypes were stable across both soil types. Usually genotypes that are stable are selected for release. These results indicate that it will be difficult for this program to consistently select genotypes with stable, high yields on both muck and sand soils. Separate tests with one set of genotypes selected from early stages on muck soils and a second set selected in early stages on sand soils are recommended for optimum genotype selection for each soil type. In these separate programs, Canal Point researchers should evaluate whether adding crop cycles to early selection stages and whether adding locations to the final selection stage on sand soils will improve selection decisions. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is one of the world's most important crops. Using a tetraploid population, we developed a linkage map using amplified fragment length polymorphism and simple sequence repeat (SSR) markers, and searched for quantitative trait loci (QTL) via interval mapping and single-marker analysis of variance. Quantitative trait loci were detected for flower color, foliage maturity, tuber skin texture, dry matter content, specific gravity, and yield. Most linkage groups were anchored to Solanum chromosomes using SSRs. The most significant QTL detected was for flower color. It was located on chromosome II and explained over 40% of the variation for this trait. This QTL most likely corresponds to the R locus for red anthocyanin production. We also confirmed the presence of QTL for foliage maturity on chromosomes Ill and V. For skin texture, a trait that has not been previously mapped in potato, we detected multiple QTL. One of these, found on chromosome III, explained 20% of the variation. By measuring specific gravity and dry matter independently we were able to detect QTL for these traits that did not co-locate, even though the traits are strongly correlated. Yield QTL were detected on multiple chromosomes, including a novel one on chromosome III. Many QTL could be modeled as simplex or duplex with dominant effects, but a large number displayed additive or interallelic interactive effects. The mapping and modeling of traits in this tetraploid population could be improved by the use of more codominant markers, such as single nucleotide polymorphisms. [ABSTRACT FROM AUTHOR]