Establishment Of Evaluation Model For Single Seed Vigor Of Rice And Molecular Mechanism Of Seed Vigor Regulation

Rice is the most important food crop in the world,which provides the staple food for60% of China’s population.The safe production of rice provides an important guarantee for China’s food security.Due to the common influence of genetic factors and environmental factors,the low seed vigor of some varieties and the decline of storage seed vigor have restricted the further improvement of rice seed quality,which has become a difficult problem affecting the development of rice seed industry.It is an effective measure to carry out individual level research on rice seed vigor,improve seed quality and ensure seed vigor to cope with a series of challenges such as the evolution of farming system and the aggravation of climate change.In this study,from the perspective of building a complete industrial chain,the optical theory and technology were applied to seed biology research,and a set of single seed vigor evaluation model was developed to realize the prediction of single grain rice seed vigor.In order to optimize this model and adapt to the actual needs of seed production and processing,the key factors affecting seed vigor were explored by using omics technology Substances and key regulatory pathways provide potential research objects for subsequent identification of characteristic activity related spectra.The main results are as follows:(1)The seed vigor phenotype of 21 varieties(materials)including Nipponbare,9311 and so on were evaluated.It was found that there were wide differences in seed vigor between individuals and populations.There were large coefficients of variation in weight gain ratio,root length and bud length among individuals.Through comprehensive analysis of various indexes of single seed vigor,it was determined that the weight gain ratio was the most effective index to reflect the difference of single seed vigor The weight gain ratio was used as the main index for the follow-up activity evaluation.(2)Based on the infrared spectrum detection theory and supercontinuum laser spectroscopy technology,a set of "spectrum vigor" evaluation model of single seed vigor of Phoebe japonica was established by partial least square regression analysis method.Through the selection of various parameters,the optimal measurement conditions were determined as light intensity 15 k Hz,integration time 50 ms,average repetition of light spectrum 5 times.Based on the analysis of the spectrum difference between the active and inactive seeds of Phoebe nipponica,it is concluded that compounds with amino N-H,hydroxyl O-H and carbonyl C = O groups may be the main reasons for the spectral differences.(3)In order to evaluate the accuracy of the "spectrum vitality" evaluation model,the model was verified by simulation,Japanese sunny sprouting verification and the model’s universality verification.The simulation results show that the model has a good effect on the evaluation and identification of seeds with different vigor gradients;78% and 85% of the original germination rate of Japanese clear seeds are evaluated and screened respectively,and the germination rate of the seed population determined as active is 98.96%,which greatly improves the germination rate of seeds;the evaluation and screening results of jianliangyou 117 of grade 93-11 show that the model can also be applied to other varieties A certain degree of applicability.(4)The proteome and metabolomic analysis of the active and inactive seeds was carried out by using the "spectrum vigor" evaluation model.The results showed that the functions of the differential proteins were the key molecules in the biochemical metabolism and signal transduction pathways,and the main metabolites were sarcosine,inositol phosphate,citric acid,ribol and so on Structure is related to function,signal transduction,electron transfer,energy supply and enzyme activity maintenance.Sugar metabolism and amino acid synthesis are the main pathways to maintain seed vigor.(5)Through gene co expression network analysis of differential protein function module and metabolite function module,multiple regulatory pathways that affect protein and metabolite simultaneously,such as salidroic acid metabolism pathway,fat metabolism,purine metabolism,pentose phosphate pathway,TCA cycle,etc.,were discovered.Key metabolites such as glyoxylic acid,adenine,nicotinic acid,d-glucose-6-phosphate,geranioid acid,etc.were discovered The results showed that nicotinic acid could significantly improve the seed vigor.