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Background: The forecasting of Coronavirus Disease-19 (COVID-19) dynamics is a centrepiece in evidence-based disease management. Numerous approaches that use mathematical modelling have been used to predict the outcome of the pandemic, including data-driven models, empirical and hybrid models. This study was aimed at prediction of COVID-19 evolution in India using a model based on autoregressive integrated moving average (ARIMA). Material and Methods: Real-time Indian data of cumulative cases and deaths of COVID-19 was retrieved from the Johns Hopkins dashboard. The dataset from 11 March 2020 to 25 June 2020 (n = 107 time points) was used to fit the autoregressive integrated moving average model. The model with minimum Akaike Information Criteria was used for forecasting. The predicted root mean square error (PredRMSE) and base root mean square error (BaseRMSE) were used to validate the model. Results: The ARIMA (1,3,2) and ARIMA (3,3,1) model fit best for cumulative cases and deaths, respectively, with minimum Akaike Information Criteria. The prediction of cumulative cases and deaths for next 10 days from 26 June 2020 to 5 July 2020 showed a trend toward continuous increment. The PredRMSE and BaseRMSE of ARIMA (1,3,2) model were 21,137 and 166,330, respectively. Similarly, PredRMSE and BaseRMSE of ARIMA (3,3,1) model were 668.7 and 5,431, respectively. Conclusion: It is proposed that data on COVID-19 be collected continuously, and that forecasting continue in real time. The COVID-19 forecast assist government in resource optimisation and evidence-based decision making for a subsequent state of affairs.

Background: Since the outbreak of coronavirus disease-19 (COVID-19) research has been continued to explore multiple facets of the disease. The objective of the present study was to evaluate the relationship between blood group phenotypes and COVID-19 susceptibility. Methods: In this retrospective observational study 132 hospitalised COVID-19 patients were enrolled from the Swai Man Singh (SMS) Medical Hospital in Jaipur, India after receiving approval from the Institutional ethics committee. The ABO, Rh and Kell blood group phenotypes along with demographic data of the patients were recorded. The observed proportions of 'A', 'B', 'AB', 'O', 'Rh' and 'Kell' blood groups in COVID-19 patients were compared against the expected proportions (the null hypothesis) of the general population using Pearson's Chi-squared test and partition analysis. Results: There were significant differences between observed and expected frequency for the ABO and Kell blood phenotypes. Further partition analysis of ABO phenotypes showed that the group 'A' phenotypes were more susceptible to COVID-19. The Kell negatives were also more susceptible. The blood groups 'AB', 'B', 'O' and 'Rh' showed no significant difference for susceptibility to COVID-19. Conclusion: The study shows a relationship between ABO, Rh and Kell blood groups and COVID-19 susceptibility. The application of these relationships in clinics should be explored in future studies.

Reliable yield performance is important in cucumber because seed companies prefer to market cultivars adapted to multiple rather than single regions of the U.S. Also, growers benefit by using a cultivar that performs well in many environments. Future performance of cultivars is also important. The objectives of the study were to (i) evaluate the yield of cucumber genotypes over successive years and in different locations, and (ii) identify cucumber genotypes with high stability for yield. A diverse set of 22 pickling genotypes was evaluated over 3 years (1986, 1987 and 1988) and in 7 locations across the United States. Yield traits were evaluated using once-over harvest and counting the number of fruit that were marketable, culled or oversize. Total yield, marketable yield (total minus culled fruit), early yield (number of oversize fruit), percent culls and fruit per plant were calculated. Data were analyzed with SASGxE and RGxE programs using SAS and R programming languages, respectively. There were strong effects of environment(E) as well as genotype(G) xE interaction for all traits. Genotypes ‘Regal F1’, ‘Calypso F1’, ‘Carolina F1’, ‘Gy 3’, ‘Gy 14’ and ‘Fremont F1’ had high marketable yield and medium to high stability for all traits. There was an advantage of hybrids over inbreds for trait performance. Hybrids fell into a single cluster with large prediction intervals. Based on the stability statistics and divisive clusters, it appears possible to breed stable cucumber genotypes with high yield. The genotype with highest performance for marketable yield, greatest stability for yield, lowest 1-R2 ratio value (diverse and representative) were ‘Marbel F1’ and Gy 14.

Cucumber (Cucumis sativus L.) germinates in an optimal temperature ranging from 24 to 28 °C. In order to develop cultivars with low temperature germination ability, knowledge regarding its genetic basis is needed. In our earlier study, we identified the accession PI 390953 as chilling tolerant and a good cold germinator. The objective of our present study was to compare cold germinability of cold tolerant breeding line B 5669 with PI 390953, and to measure the inheritance of this trait. At 13 °C, both tested cultigens (B 5669, PI 390953) showed the highest germinability and we found no significant differences between them regarding the rate of germination, days to germination (DTG), or germination index (GI). We also observed differences in the germination ability at 13 °C among seven hybrid populations of cucumber, derived from the cross between good cold germinator B 5669 (P1) and B 6115 (P2) lacking cold-germination ability. The fastest low temperature germination and the highest low temperature germination percentages were observed in B 5669 (P1) with germination of 78 and 100% on the 6th and 10th day of the test, respectively. In addition, the cultigen B 5669 exhibited the fastest germination, reaching on average of DTG = 5.7. B 6115 (P2) and BC1P2 proved unable to germinate at 13 °C even within 21 days. The seed germinability of F2 population fits a three-recessive gene model. Cucumber cultigens B 5669, PI 390953, and PI 246903 showed low temperature tolerance, but of them B 5669 may become the most desirable to breeders since it exhibits cold germinability combined with good fruit quality traits.

Powdery mildew caused by Podosphaera xanthii has recently become an important disease of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] in the United States. The disease can be controlled with fungicides, but it would be more economical and environmentally safe to use genetic resistance. Here, we report sources of resistance to powdery mildew race 2W identified in the evaluation of the entire U.S. watermelon Plant Introduction collection made of four Citrullus Schrad. ex. Eckl. & Zeyh. species and Praecitrullus fistulosus (Stocks) Pangalo species. A total of 1654 PI accessions, cultivars, and breeding lines (hereafter collectively referred to as cultigens) were tested in the greenhouse using at least seven replications. From that, 54 cultigens including the 44 most resistant and 10 susceptible checks were retested in greenhouse and field experiments. All cultigens showed symptoms of powdery mildew. Resistance was identified in wild PI accessions. Eight cultigens had high resistance and 21 had intermediate resistance. Leaf and stem disease severity ratings were positively correlated (r = 0.86, P < 0.0001). Data were summarized from the screening and retest studies, and the most resistant cultigens were PI 632755, PI 386015, PI 189225, PI 346082, PI 525082, PI 432337, PI 386024, and PI 269365. The most susceptible cultigens were PI 222775 and PI 269677. Many of the resistant cultigens originated from Nigeria and Zimbabwe. doi: 10.2135/cropsci2009.03.0135

A study measured the inheritance of novel rind phenotypes and verified the genetics of white, red, salmon yellow, and canary yellow flesh colors of watermelon. The inheritance of the C gene for the canary yellow flesh color was verified as single dominant, and a new inbred type line was developed possessing that gene.

Gummy stem blight, caused by Didymella bryoniae (Auersw.) Rehm, is a major disease of watermelon [Citrullus lanatus (thunb.) Matsum. & Nakai]. Plant breeders need sources of resistance that can be incorporated into adapted breeding lines to help control the disease. We tested all the available accessions from the USDA-ARS watermelon germplasm collection, including C. lanatus var. citroides (L.H. Bailey) Mansf., for resistance to gummy stem blight. The experiment was a randomized complete block with 1332 cultigens, two sites (field and greenhouse), two or four replications, and two to six plants per plot. The resistant check was PI 189225 and the susceptible check was 'Charleston Gray'. PI 279461, PI 482379, PI 254744, PI 526233, PI 482276, PI 271771, PI 164248, PI 244019, PI 296332, and PI 490383 were selected as the most resistant cultigens to be used in future breeding efforts. The most susceptible cultigens were PI 183398, PI 169286, PI 223764, PI 226445, PI 525084, PI 534597, and PI 278041., WATERMELON is a major vegetable crop in the USA, with a total production in 2001 of about two million megagrams of marketable fruit (USDA-ARS, 2001). Gummy stem blight caused by [...]

High yield is a major goal for watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] breeders. The objective of this study was to measure yield in a diverse set of watermelon cultivars to identify high-yielding germplasm for use in breeding programs. Phenotypic variation for fruit yield in a diverse set of 80 watermelon cultivars was studied in the field in North Carolina. Yield was evaluated in replicated experiments of three environments (combinations of 2 yr and two locations), and two to four replications per environment. Plots were harvested one to two times, depending on the average maturity of the fruits at the first harvest. The highest yield overall was obtained from 'Mountain Hoosier' and 'Starbrite'. Some of the new, elite hybrid cultivars were in the top-yielding group, but there were old, inbred cultivars in the top group as well. Consistent and significant yield differences among the 80 cultivars across environments indicates genetic variation for the trait, in addition, high-yielding cultivars for use in breeding programs were identified. Watermelon breeders interested in developing new, high-yielding cultivars should make use of top performers in this study in their breeding programs., HIGH YIELD IS A major goal for watermelon breeders (Mohr, 1986). Earlier efforts in watermelon breeding involved development of new cultivars of different types with high fruit quality and early [...]

A survey was conducted to identify land-grant universities in the USA having plant breeding programs, and to determine the number of domestic and international plant breeding students graduating at the M.S. and Ph.D. levels from those programs in 1995 to 2000. A total of 71 U.S. land-grant universities were identified. There were 409 (53%) Ph.D. and 361 (47%) M.S. degrees awarded. Of the total, 362 (47%) graduates were domestic and 408 (53%) were international. There was no major change in the total number of plant breeding graduates during the 6-yr period. The largest numbers of plant breeding students were trained in agronomy (crop science) departments, followed by plant breeding departments or groups, horticulture departments, plant science departments, and combined agronomy--horticulture departments. Universities with an average of seven or more graduates per year were University of Wisconsin-Madison, North Carolina State University, University of Nebraska-Lincoln, Cornell University, University of Minnesota-St. Paul, Iowa State University, and Texas A&M University. The downward trend noted in previous surveys has continued to the point where there are only a few universities with large plant breeding programs remaining in each region of the country. If the USA is going to continue its public effort in plant breeding research and graduate student training, sufficient federal and state funding will have to be provided to support at least the current regional centers., FOR THE PAST SEVERAL YEARS, there have been concerns in the public and private plant breeding sectors about the future availability of plant breeding graduates to work at seed companies [...]