Study On Characters Of Root Morphology And Matter Accumulation Among Maize, Perennial Teosinte And Their F1Hybrids

To analysis the root morphology index, contents of soluble sugar and dry matter contents on the ground and underground, in the6physiological periods from tillering stage to withering period, we studied the annual and perennial materials in diploid maize (Mo17), tetraploid perennial maize (9475), diploid perennial maize (TZ11), the self-made allodiploid (Mol7X Tzll), allotriploid (Mo17×9475), allotetraploid (438×9475, and438is the autotetraploid maize.). The aim of our study was to find the difference of root system and physiological character in annual, perennial, and their hybrids, which could find the reasons of perennial structure and character, and could offer the scientific evidence to perennial maize breeding. And there are the results:1. The analysis on the6indexes, including the length, proportion and others in the materials from tillering stage to withering period suggested1) the7indexes of all materials show rapid upward trends in all atages;2)from the tasseling stage to the pustulation period, the roots of Mo17and438X9475showed slow growth trends, while that of TZ11,9475, Mol7×Tzl1, Mo17×9475increase rapidly;3) from the pustulation period to the withering period, the indexes of Mo17and438×9475had declining trends, while some of that in materials of TZ11,9475, Mo17×Tzl1, Mo17×9475still increased, such as root volumn of Mol7*9475and the total length of Mo17×Tzl1;4) in the withering period, the root proportions of TZ11,9475, Mo17×Tzll and Mo17×9475were significantly highier than that of Mo17and438×9475. And the Mo17and438×9475were shown to be annual, while TZ11,9475, Mo17×tzll and Mo17×9475were perennial. Therefore, the growth changes in both annual and perennial materials were the same, which had much difference in periods from the tasseling stage to the withering period.2. The analysis on soluble sugar from the6stages in the overground and underground parts suggested that:1) in the overground part, all indexes show declining trends from the tillering stage to the elongation stage;and from the elongation stage to the booting stage, indexes of all materials decline, expect that of Mo17; from then to the pustulation period stage, the figures all show upward trends; and from booting stage to the pustulation period period, the content of soluble sugar in overground part in Mo17was signigicantly higher than that in TZ11,9475, Mo17×Tzl1, Mo17×9475and438×9475; and from the pustulation period to the withering period, the indexes of all materials had increasing trends, except that in Mo17and Mo17×TZl1.These mean the content of soluble sugar in overground parts of our materials have the same tendency in most growth stages, which was quite different from the pustulation period to the withering period.2) in the underground part, the indexes in all materials from the tillering stage to the elongation stage increase; and from the elongation stage to the booting stage, the figures show decreasing trend, except that of9475, which had the opposite tendency; in the next stage, all indexes drop; from the tasseling stage to the days of pustulation period, the figures were all rising; in the last stage, the indexes show the upward tendency, except the declining one in Mo17×TZl1.And in this period, the indexes of9475and Mo17×9475were signicificantly higher than that of others. Therefore, soluble sugar showed the physiological status in the different parts of materials may have corrosponding with the resistance.3. The analysis on dry matter accumulation from the6stages suggested that:1) in the overground part, from the tillering stage to the days of pustulation period, the indexes were all rising; in the other stages, the indexes had the upward trends, except that of438×9475and9475, which showed downward trends. And in all growth periods, dry matter accumulation in Mo17(annual material) showed a slow increase, and from the tasseling stage on, the accumulation was significantly lower than that of other ones; in another annual material,438X9475, the accumulation had a high peak, and the varietion trend was similar to that of other perennial ones.2) in the underground part, the indexes rose, from the tillering stage to the tasseling stage; from then to days of pustulation period, the indexes showed upward trends, except the declining one of9475; in the other stage, the indexes decline, which were rising in438×9475and Mo17×9475. And accumulation of dry matter of the perennial materials of Mo17×9475,438X9475and Mo17hadthe slow increasing tendency.3) to both overground and underground part, from the tillering stage to the elongation stage, the indexes go up; in the second period, the figures went down; from the booting stage to the tasseling stage, the trend turns back again; in the next stage, from days of tasseling to the pustulation period, the indexes decline;in the last stage, the indexes go down persistently, except the rising ones of Mo17×9475and438×9475. This came to the result that, from the tillering stage to the tasseling stage, the varietion trends of indexes were almost the same, and they have the similar growth models; in the other stages, the trends of figures became different, but there was no significant difference between annual and perennial materials.