Special genes are expected to reveal the selection process of domesticated corn in ancient times

<

Scientists in the United States reported on the 2nd issue of Nature that they have discovered special genes that control the branching of maize plants. The gene is expected to reveal how the ancients chose the species during the domestication of corn. From an evolutionary perspective, the Native Americans first transformed Mexican melons into modern maize 3,000 years ago. In the 1920s, scientists discovered a variant of maize in South America that does not branch or bloom. Scientists at the University of California in the United States recently conducted research on this type of corn and found that the cause of this anomaly in corn was the mutation of a gene called "Balchi 1". The "bush stalk 1" gene in normal maize controls the branching of crops, and the position of the gene in the maize gene map is just in a special genetic region, which plays a key role in the domestication of corn. In more in-depth studies, the scientists compared the existing wild species in Mexico with modern maize. As a result, it was found that there are 12 "Butterfly 1" varieties commonly found in wild fleas, and each variety will affect the growth of different types of twigs. In modern corn, there is only one "bush stalk 1" gene. This shows that the American Indians will screen out other species with a variety of "Butter Stem 1" during the domestication of corn. The researchers said that their next step is to introduce all the current genetic variations of the "Bush 1" gene into modern maize. This is expected to enable scientists to infer that the ancients made a The choice affects the shape of modern corn.

Indicator
SanQiang medical companies specializing production Indicator.
Medical Indicator in the verification of the sterilization procedure,although the sterilization effect can be evaluated through the monitoring of certain parameters of the sterilization process,the degree of killing of the biological indicator is the most intuitive indicator for evaluating the effectiveness of a sterilization procedure.Commercially available standard biological indicators can be used,as can spores prepared with the most resistant micro-organisms isolated during daily production monitoring of contaminants.In the biological indicator verification test,the D value of the spore under the actual sterilization condition needs to be determined,and the spore purity and quantity are determined.When verifying,the microbial indicator of the biological indicator should be larger than the routine detection of microbial contamination,and the tolerance is strong to ensure that the sterilization procedure has greater safety.In the final sterilization method,biological indicators should be placed in different parts of the sterilizer.And avoid direct contact with the indicator to be sterilized items.The biological indicators are sterilized after being sterilized according to the set conditions,and cultured in a culture medium respectively to determine whether the spores in the biological indicator are completely killed.
Medical indicator in the sterilization biomonitoring of medical indicator,the standards 

Indicator

Medical Indicator,Chemical Indicator Tape,Plasmas Indicator,Self Contained Indicator

Henan Sanqiang Medical Equipment Liability Co.,Ltd , http://www.sterilizers-china.com