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Sweetpotato (Ipomoea batatas L), the herbaceous plant cultivated for its starchy storage roots, has a complex genome (2n = 6x = 90) with the estimated genome size of about 4.5 GB. Albinism, a phenomenon that occurs in plants, is defined as the total pigment loss accompanying with insufficient chloroplast membrane differentiation. For this study, an identified natural albino mutant of Xuzi-8 cultivar was subject to RNA sequencing relative to the green plants of identical cultivar. The results showed that total chlorophyll, chlorophyll a, chlorophyll b, and carotenoids were significantly lower in albino plants than in normal green plants. In addition, the CO2 assimilation rate, intercellular CO2 concentration, conductance level, and transpiration rate were significantly higher in normal green plants than in albino mutants. High-quality reads in the total number of 27,520,273-39,862,794 were obtained following the removal of the potentially contaminated or low-quality reads from the albino-mutant and normal green sweetpotato libraries. Later, sequences were matched with the available online data of Ipomoea batatas, and a very low matching degree (2.22%) was obtained, which indicated the very few available data of Ipomoea batatas genome compared with other plants. Additionally, the obtained unigenes were conducted functional annotations and classification, including GO, KOG, and KEGG analyses. The significance level and DEGs differences between albino-mutant and normal green plants were determined according to the thresholds of FDR ≤ 0.001 and log2 FC ≥ 1. A total of 3000 unigenes were upregulated in albino mutants but normally expressed in normal green plants. These genes were involved in facilitating plant nutrition sources depending on the stored carbohydrates and fats. Furthermore, these unigenes were aligned to the DDP family zinc finger protein, glycerophosphodiester phosphodiesterase, beta-galactosidase, GDE-like, and SELMODRAFT PDDEXK. On the other hand, altogether, 2418 unigenes were downregulated in albino-mutant plants compared with normal green plants, which were responsible for chloroplast differentiation and development, chlorophyll degradation, and synthesis of other pigments. Therefore, they might be related to the defect that caused this mutant.

Abstract Background: Purple-fleshed sweetpotato (PFSP) is one of the most important crops in the word which helps to bridge the food gap and contribute to solve the malnutrition problem especially in developing countries. Salt stress is seriously limiting its production and distribution. Due to lacking of reference genome, transcriptome sequencing is offering a rapid approach for crop improvement with promising agronomic traits and stress adaptability. Results: Five cDNA libraries were prepared from the third true leaf of PFSP at seedlings stage (Xuzi-8 cultivar) treated with 200 mM NaCl for 0, 1, 6, 12, 48 hours. Using second and third generation technology, Illumina sequencing generated 170,344,392 clean high-quality long reads that were assembled into 15,998 unigenes with an average length 2178 base pair and 96.55% of these unigenes were functionally annotated in the NR protein database. A number of 537 unigenes failed to hit any homologs which may be considered as novel genes. The current results indicated that sweetpotato plants behavior during the first hour of salt stress was different than the other three time points. Furthermore, expression profiling analysis identified 4, 479, 281, 508 significantly expressed unigenes in salt stress treated samples at the different time points including 1, 6, 12, 48 hours, respectively as compared to control. COG analysis revealed that the highest number of genes was categorized as “post-translational modification, protein turnover, chaperones” followed by “signal transduction mechanisms”. Gene ontology (GO) enrichment analysis showed that salt stress caused changes in metabolic process (Secondary and amino acids), hormone response, cellular processes and single organism processes. These findings suggest that salt stress tolerance in PFSP plants may be mainly depended on three factors including the balance between protein biosynthesis and degradation, preventing or correcting damage caused by miss-folding due to salt stress and transforming the certain stimulus induced by salt stress into a biochemical signal which activates more genes specifically involved in salt stress tolerance.

Image segmentation is one of the key steps in image analysis, where the fuzzy theory based methods are widely used?but, none had universally property to segment all types color images. So, to improve segmentation quality and universally property of segmentation algorithm, a new fuzzy color image segmentation algorithm was brought out based on feature divergence and fuzzy dissimilarity. The algorithm measured the otherness of two stylebooks space eigenvector by feature divergence, and extracted sub-images feature eigenvector using watershed algorithm, depressed operation data number. Combination of sub-image was done by dint of fuzzy dissimilarity and morphological theory, and the isolated points were eliminated, and made color image segmentation more according with the human segmentation strategy. The method efficiency and feasibility were confirmed by experimental results.

The Fourier spectrum characters of the almost perfect binary array pair are studied, which is based on the concept of the almost perfect binary array pair. The distributions of the weights, existent range and the imbalance of almost perfect binary array pair are given by using this spectrum characters.