The Genetic Basis Of The Compatibility Of Abiotic Resistance And High Yield In Panicum Miliaceum

Millet(Panicum miliaceum L.)originated in China and is the earliest domesticated important crop in ancient China.Millet is the staple food of the people in areas such as sub-Saharan Africa,India,and South Asia in arid and semi-arid regions.Its nutritional value is high and it has a unique role in balancing diets and promoting human health.Screening and cultivating the salt-tolerant millet to adapt to salinized land is an important way to increase grain yield.Therefore,it is necessary to study the salt tolerance of different varieties of millet.In this study,the two varieties of millet,Pinmei 3 and Yumei 2,have different salt tolerance: Yumei 2,compared with the Pinmei 3 has more salt tolerance.Using statistical methods,comprehensive evaluation of the salt tolerance and rehydration physiological characteristics of Pinmei 3 and Yumei 2 will provide abundant raw materials for the further utilization of millet.In this experiment,the salt tolerance of Yumei 2 was slightly stronger than that of Pinmei 3.Therefore,the plant height of Yumei 2 was higher than Pinmei 3 and the root length was longer during the salt treatment.In salt treatment and rehydration,to reach the same damage extent,Yumei 2 needs to be treated with nutrient solution containing higher concentration salt,but its rehydration time is longer than that of Pinmei 3.In the rehydration process,the plants of Yumei 2 are also taller than that of the Pinmei 3.Cultivation of millet by hydroponics can give them more nutrients and water,making them more robust and prosperous.Previous literature has shown that hydroponic conditions has no or very little influence on Arabidopsis thaliana,and in particular it reduces the restriction on roots.Therefore,the Arabidopsis plants under hydroponic conditions is much taller than those growing in the soil,and the root system is more developed and propagated.The seeds are also more full.In this experiment,hydroponics was used to study the salt-tolerance physiological characteristics of different millet varieties during salt treatment and rehydration.In the salt tolerance experiment,we found that for Pinmei 3,a salt concentration of 100 mM can result in about 50% mortality rate,while for Yumei 2,the salt concentration of 200 mM caused approximately 50% of plant mortality rate,Therefore,in rehydration test after salt treatment,Pinmei 3 was treated with a nutrient solution containing 100 mM NaCl,while Yumei 2 treated with a nutrient solution containing 200 mM NaCl.As a result,it was found that both Pinmei3 and Yumei 2 have certain compensatory growth capabilities.The absorption efficiency of nitrogen and phosphorus is a key factor that limits the growth and yield of crops.Therefore,it is very important to develop new varieties of crops with efficient utilization of nitrogen and phosphorus.In our country,millet is a traditional coarse grain crop with drought tolerance and other stress resistances.Pinmei 3 and Yumei 2 used in this study were periodically watered with nutrient solutions containing different concentrations of N and P under sand culture.The results showed that Pinmei 3 grew well in a nutrient solution containing 15 mM nitrogen or in the nutrient solution containing 1 mM phosphorus,while the Yumei 2 grew stronger in the nutrient solution containing 30 mM nitrogen or in the 2 mM phosphorus medium.Therefore,it can be preliminarily presumed that the responses of different millet varieties to high-fertilizer,especially to high-nitrogen and high-phosphorus,are different.In the millet planting industry,after statistics,the output of Pinmei 3 is 150-250 kg,and that of Yumei 2 is 200-250 kg and the highest is 300 kg.Combining with the experimental results,we know that Yumei 2 has shown stronger resistance than Pinmei 3 no matter in response to salt stress or in high fertilizer response.Therefore,it is speculated that the high yield and resistant to an adverse environment may be compatible.As a major cultivated crop in arid and semi-arid regions,it has a unique nutritional value and medicinal value.The construction of high yield and high efficiency production system of millet in arid region and the genetic basis of high yield of millet under adverse conditions are the important directions for the future development of millet.