Mulching broad ridges with a woven polypropylene fabric increases the growth and yield of young pear trees ‘Yuluxiang' in the North China Plain

Unlike traditional ridging, mulching broad ridges with a woven polypropylene fabric (WPF) can reduce soil evaporation during the drought season and avoid long saturation time in the root zone of pear trees during the rainy season. In this study, field experiments were conducted from 2017 to 2020 in a pear orchard in the North China Plain to investigate the effects of mulching broad ridges (0.3 m in height and 2 m in width) with WPF on soil temperature and moisture, nitrogen leaching, vegetative and reproductive growth of young pear trees(Pyrus bretschneideri Rehd.‘Yuluxiang’). The experiments involved two treatments, namely, control (traditional no-ridge planting without mulching) and mulching broad ridges with WPF (RM treatment). The results showed that the RM treatment increased soil moisture and temperature and decreased nitrogen leaching, resulting in vigorous growth of the young pear trees. Moreover, the RM treatment increased the tree trunk cross-sectional area and height of the young pear trees by 37%and 8%in 2020, respectively. The nitrate nitrogen content at the soil layer depth of 0-30 cm was significantly higher in the RM than that in control. Furthermore, the RM treatment significantly increased the fruit yield due to larger tree size. In addition, compared with control, significantly higher fruit soluble solid content of RM treatment was detected in 2020. High precipitation (423 mm) occurred during fruit enlargement stage in 2020, RM treatment decreased the rainfall infiltration in the ridge and the soil moisture in root region, resulting in the improvement of fruit quality, compared with control.Therefore, mulching broad ridges with WPF can be implemented to increase soil moisture during drought season, soil temperature, and nitrate nitrogen content, thereby improving the growth and fruit yield of young pear trees. Additionally, it can reduce soil moisture in the root zone during the rainy season and improve the fruit quality of the trees. Finally, it can reduce nitrate nitrogen leaching, thereby reducing environmental pollution.

Functional identification of lncRNAs in sweet cherry(Prunus avium)pollen tubes via transcriptome analysis using single-molecule long-read sequencing

Sweet cherry(Prunus avium)is a popular fruit with high nutritional value and excellent flavor.Although pollen plays an important role in the double fertilization and subsequent fruit production of this species,little is known about its pollen tube transcriptome.In this study,we identified 16,409 transcripts using single-molecule sequencing.After filtering 292 transposable elements,we conducted further analyses including mRNA classification,gene function prediction,alternative splicing(AS)analysis,and long noncoding RNA(lncRNA)identification to gain insight into the pollen transcriptome.The filtered transcripts could be matched with 3,438 coding region sequences from the sweet cherry genome.GO and KEGG analyses revealed complex biological processes during pollen tube elongation.A total of 2043 AS events were predicted,7 of which were identified in different organs,such as the leaf,pistil and pollen tube.Using BLASTnt and the Coding-Potential Assessment Tool(CPAT),we distinguished a total of 284 lncRNAs,among which 154 qualified as natural antisense transcripts(NATs).As the NATs could be the reverse complements of coding mRNA sequences,they might bind to coding sequences.Antisense transfection assays showed that the NATs could regulate the expression levels of their complementary sequences and even affect the growth conditions of pollen tubes.In summary,this research characterizes the transcripts of P.avium pollen and lays the foundation for elucidating the physiological and biochemical mechanisms underlying sexual reproduction in the male gametes of this species.

Chromosome-level genomes of seeded and seedless date plum based on third-generation DNA sequencing and Hi-C analysis

Diospyros lotus L.(Date plum)is an important tree species that produces fruit with a high nutritional value.An accurate chromosomal assembly of a species facilitates research on chromosomal evolution and functional gene mapping.In this study,we assembled the first chromosome-level genomes of seeded and seedless D.lotus using Illumina short reads,PacBio long reads,and Hi-C technology.The assembled genomes comprising 15 chromosomes were 617.66 and 647.31 Mb in size,with a scaffold N50 of 40.72 and 42.67 Mb for the seedless and seeded D.lotus,respectively.A BUSCO analysis revealed that the seedless and seeded D.lotus genomes were 91.53% and 91.60%complete,respectively.Additionally,20,689(95.4%)and 22,844(98.5%)protein-coding genes in the seedless and seeded D.lotus genomes were annotated,respectively.Comparisons of the chromosomes between genomes revealed inversions and translocations on chromosome 8 and inversions on chromosome 11.We identified 490 and 424 gene families that expanded in the seedless and seeded D.lotus,respectively.The enriched pathways among these gene families included the estrogen signaling pathway,the MAPK signaling pathway,and biosynthetic pathways for flavonoids,monoterpenoids,and glucosinolates.Moreover,we constructed the first Diospyros genome database(http://www.persimmongenome.cn).On the basis of our data,we developed the first high-quality annotated D.lotus reference genomes,which will be useful for genomic studies on persimmon and for clarifying the molecular mechanisms underlying important traits.Comparisons between the seeded and seedless D.lotus genomes may also elucidate the molecular basis of seedlessness.

Development of a molecular marker for cherry crinkle leaf disease

Sweet cherry(Prunus avium L.)is an economic fruit tree of the Prunus genus in the Roaceae family(Vignati et al.2022).It is popular with consumers because of its early ripening in open-field,bright color,and rich nutrition.Since the 80’s,sweet cherry industry in our country has developed rapidly.At present,the production,planting area and import of sweet cherry are ranked first in the world,which is known as‘gold planting industry’(Zhang et al.2020).