Breeding Of Early-maturating And Fragrant Rice Via CRISPR/Cas9 Mediated Genome Editing

Heilongjiang province was one of the most important rice cultivation regions of China.In the past years,with the ever-increasing of rice growth,Heilongjiang province had became the largest rice planting region in China.However,limited by low temperature and long day condiation,some later flowering elite rice can`t be cultivated in the high latitude zone.Thus,lacking of earlier flowing elite rice in the high latitude zone has became the key problem for Heilongjiang province rice production.Heading Date（HD）is one of the most important agronomic traits which determined the cultivated area.Fragrant rice is more popular than common rice.So in this study,we attempted to created early-maturating and fragrant rice via CRISPR/Cas9 mediated genome editing.Main results are as follows:1.Hd2/OsPRR37,Hd4/Ghd7,Hd5/DTH8/Ghd8 and Badh2 were edited by CRISPR/Cas9 mediated genome editing in 5 major cultivated varieties of Heilongjiang province and 2 elite cultivars of south of China.2.In T1 generation,the homozygous lines were preliminarily selected by phenotypic observation,and then confirmed by sequence analysis.i3.In T₂ generation,the T-DNA insertion fragment,including the CRISPR/Cas9 and the antibiotics selection marker was removed.The homozygous edited lines flower significantly earlier than the parent.4.Seeds aromas of edited lines were preliminarily analyzed by chewing and potassium hydroxide extraction assay.Gas Chromatography–Mass Spectrometry（GC-MS）assay was further performed to quantify the aroma compound,2-acetyl-1-pyrrolin（2-AP）in mature seeds.the result show that the edited lines were fragrant compared parents.