In this study, two different hybrids of Easter lily (Lilium longiflorum), obtained from two cross combinations, along with their four parents were sequenced by high-throughput RNA-sequencing (RNA-Seq) to find out differentially expressed gene in parent-hybrid combinations. The leaf mRNA profiles of two hybrids and their four parents were RNA-sequenced with a view to identify the potential candidate genes related to plant height heterosis. In both cross combinations, based to morphological traits mid-parent heterosis (MPH) was higher than high-parent heterosis (HPH) for plant height, leaf length, and number of flowers whereas HPH was higher than MPH for flowering time. A total of 4,327 differentially expressed genes (DEGs) were identified through RNA-Seq between the hybrids and their parents based on fold changes (fc) ≥ 2 for up-and ≤-2 for down-regulation. Venn diagram analysis revealed that there were 703 common DEGs in two hybrid combinations, those were either up-or down-regulated. Most of the commonly expressed DEGs exhibited higher non-additive effects especially overdominance (75.9%) rather than additive (19.4%) and dominance (4.76%) effects. Among the 384 functionally annotated DEGs identified through Blast2GO tool, 12 DEGs were up-regulated and 16 of them were down-regulated in a similar fashion in both hybrids as revealed by heat map analysis. These 28 universally expressed DEGs were found to encode different types of proteins and enzymes those might regulate heterosis by modulating growth, development and stress-related functions in lily. In addition, gene ontology (GO) analysis of 260 annotated DEGs revealed that biological process might play dominant role in heterotic expression. In this first report of transcriptome sequencing in Easter lily, the notable universally up-regulated DEGs annotated ABC transporter A family member-like, B3 domain-containing, disease resistance RPP13/1, auxin-responsive SAUR68-like, and vicilin-like antimicrobial peptides 2-2 proteins those were perhaps associated with plant height heterosis. The genes expressed universally due to their overdominace function perhaps influenced MPH for greater plant height-largely by modulating biological processes involved therein. The genes identified in this study might be exploited in heterosis breeding for plant height of L. longiflorum. Heterosis refers to the higher performance in any trait (s) of interest of F 1 hybrid as compared to homozygous parental lines. Charles Darwin 1 described this phenomenon for the first time ever and later Shull 2 and East 3 independently confirmed this phenomenon. Improvements in many traits of different crop and livestock species have

No abstract

No abstract

It has been a serious problem that flower buds of camellia (Camellia spp.) drop very easily when they are grown under unfavourable indoor conditions. To examine the factors affecting flower bud abscission, some cultivars of potted camellia (Camellia japonica L.) moved to various indoor conditions from greenhouse after flower buds were well developed. In general, double flowering cultivars showed more flower bud abscission than single flowering cultivars. Relative humidity (RH) severely influenced flower bud abscission. In `Beniodome' camellias, flower bud abscission reached to 90% under arid condition (30% RH) which resulted in very poor flowering (8%), whereas flower bud abscission recorded only 5% under humid condition (80% RH) which resulted in abundant flowering (90%). Flower bud abscission of camellias was little influenced by light intensity. Plants applied with 500 ppm ethephon produced a lot of ethylene and abscised all flower buds within a month. Ethylene accelerated the development of the abscission layer of camellia pedicels. Spray with 2 mM silver thiosulfate (STS) effectively prevented flower bud abscission of potted camellias. Polygalacturonase activity of abscission zones was correlated with the increase of flower bud abscission in camellias.

No abstract