Studies On The Heredity, Growth And Development, Physio-Biochemistry Of Albino-lemma Barley

An albino-lemma mutant was isolated from barley which were treated with r-ray radiation. The albino-lemma mutant was modified and improved in BaYMV (Barley Yellow Mosaic Virus) resistance, and then one albino-lemma mutant line was selected. Using the mutant line, two pairs of NIL(near isogenic line) was established from segregating in high generation of cross. The NILs were used to analyze the heredity and compare plant growth, grain development and quality, lemma's microstructure, chlorophyll of leaves and awns, awns function, the change of enzyme and other traits. The main results as follows:(l)The analysis of albino-lemma heredity showed that: albino-lemma is controlled by single recessive gene which is pleiotropic; the albino-lemma gene is independent with the black-lemma gene which has epistatic dominance over the albino-lemma gene.(2)Through comparing in NILs, AL (Albino-lemma line) is similar with NL (Normal-lemma line) in such traits as tilling ability, effective ears, grains per ear, setting rate, hull percentage, plant height, anti-lodging, some diseases resistance and lemma's developing. But it has negative effective in seedling rate. AL's growth duration is longer, the accumulation of grain is inferior to NL. So the grain weight of AL is decreased , that lead to declining in yield (over 10%). This means green lemmas and pericarp have some contribution to grain yield.(3)The lemma's microstructure was observed and analyzed. It displayed that the plastids havn't differentiated in albino-lemma's thin cells, resulting in the white lemma. The outer structures of either outer epidermis or inner are similar between AL and NL. They both possess short or long hairs and stomata. But the tubercles on outer epidermis are more obvious in AL than in NL, indicating AL's outer cells have high silicious degree.(4)By analyzing the grain quality, it was showed that: albino-lemma has negative effects on grain's plumpness, but different with lines. This means lines with good plumpness can be selected. AL's grains always have higher protein content and lower pro-anthocyanidin content than NL's. So the albino-lemma may be a useful marker in breeding.(5)The chlorophyll content of leaves and awns (after heading ), awns function were tested, the results showed that: AL's chlorophyll content is higher than NL's in either leaves or awns, and AL's awns function are higher than NL's. It is possible that plant has self-regulation ability, through regulation, AL's leaves and awns canmake up some losses caused by deficient chloroplast in grains. It was suggested that high yield of AL can be obtained by selecting lines with strong compensating ability.(6)The enzymes were analyzed and compared, it was showed that during grain development, AL's PAL activity is lower than NL's in later stage. That may responsible for the lower pro-anthocyanidin content in AL. AL's POD activity is always higher than NL's, this may has relation with deficient chloroplast in grains which may change the process of development and metabolism. There were no significant difference of esterase isozymogrames in both leaves (tilling and heading stage) and grains between AL and NL. AL's and NL's peroxidase isozymogrames have no difference in leaves (tilling and heading stage). But significant difference in grains, AL has one more band in peroxidase isozymogrames than NL, the other band are same. It was indicated that the albino-lemma gene has no relation with esterase, but close relation with peroxidase, which was specifically expressed in the grains.Finally, mutant's traits and utility were discussed and a conclusion was made.