| In order to provide a theoretic foundation for super high yield breeding of different eco-regions in the Yangtze River Basin,this thesis studied the objective traits of super hybrid rice systematically.Nine certificated super hybrid rice combinations and two new combinations with super high yield potential were used as the test materials with the check of Shanyou63-the most popularized three-line combination with high yield in China.They were planted in seven different eco-regions of six provinces(cities) in the Yangtze River Basin.The adaptability of different super hybrid rice combinations was dissimilar in different eco-environments.Super hybrid rice of wide-adaptability,such as Zhunliangyou 527,Honglianyou 6,C liangyou 87 and Y liangyou 1 were suitable for planting in most eco-regions in the Yangtze River Basin.Super hybrid rice of regional-adaptability,for example,88S/0293 and Liangyoupeijiu were only suitable for planting in some special eco-regions.Seed-setting percentage was the most important index to examine the wide-adaptability of super hybrid rice combinations.Super hybrid rice could be divided into six types according to the characteristics of dry matter accumulation and translocation.The first type was the high dry matter accumulation and high economic index type,such as Zhunliangyou 527.The second type was the high dry matter accumulation and medium economic index type,such as Honglianyou 6 and Y liangyou 1.The third type was the high dry matter accumulation and low economic index type,such as Xieyou 9308 and 88S/747.The forth type was the medium dry matter accumulation and high economic index type,such as C liangyou 87.The fifth type was the low dry matter accumulation and high economic index type,such as GD-1S/RB207.The sixth type was the medium dry matter accumulation and medium economic index type,such as 88S/0293,Ⅱyouming 86, Liangyoupeijiu and Guodao 1.Basic leaf angle of the top-three leaves was the first principal component to affect the leaf posture of super hybrid rice at booting stage.The basic leaf angles of super hybrid rice of wide-adaptability were about 5°,10°and 15°for the flag,2nd top and 3rd top leaf,respectively,at booting stage,and nearly 10°,15°and 20°at full heading stage.Leaf drooping angle of the top-three leaves was the first principal component to affect the leaf posture of super hybrid rice at full heading stage,and the leaf drooping angle of super hybrid rice of wide-adaptability was from 0.5°to 1.8°,from 1.4 to 5.2°and from 2.0 to 6.2°for the flag,2nd top and 3rd top leaf,respectively.The correlation between basic leaf angle,leaf drooping angle of the upper 3 leaves and yield was negative and the correlation was remarkably negative between the leaf drooping angle of the flag leaf and the 3rd top leaf and yield at full heading stage. Leaf rolling index was an important objective trait for the plant-type of super hybrid rice.Length and area of the upper 3 leaves were the first principal components to affect the leaf morphology of super hybrid rice.Longer and larger functional leaves could have an adverse influence on yield.The correlation was remarkably negative between the length of upper 3 leaves and yield and between the area of flag leaf and yield,negative between the area of upper 3 leaves and yield,and between the length/width ratio of upper 3 leaves and yield and it was highly remarkably negative between length/width ratio of the 2nd top leaf and yield.Length of the upper 3 leaves of super hybrid rice of wide-adaptability was from 34.8 to 43.1cm of the flag leaf, from 44.6 to 53.9cm of the 2nd top leaf and from52.9 to 56.7cm of the 3rd top leaf and the length/width ratio was from 17.8 to 23.8,from 28.3 to 32.7 and from 37.7 to 41.2, respectively.Increasing the length of upper 3 leaves within an appropriate range of length/width ratio could increase yield of super high yield through improving light energy utilization of the population.The specific leaf weight of super high rice was higher than that of the check in the same leaf position.The flag leaf of super hybrid rice of wide-adaptability had higher photosynthesis ability and physiological activity in late growth period because its specific leaf weight at the dough stage was higher than that of the 2nd and the 3rd top leaves,and higher than that of the same leaf position at milking stage.The first principal factor of economic characteristics of the super hybrid rice was co-decided by number of spikelets per panicle,spikelet density,the number of unfilled grains per panicle and seed-setting percentage.However,the first principal factor of economic characteristics varied with different combinations.There existed a positive correlation(but not significant) between the grain-leaf ratios and yield of super hybrid rice at full heading stage.However,the negative correlation was highly remarkable between the grain-leaf ratio and the 1000-grain weight.The effective panicle number was down in super hybrid rice with the longer leaf and bigger area leaf,and correlation was remarkably negative between the effective panicle number per plant and the length,area of upper 3 leaves.And longer panicles of super hybrid rice could cause the drooping functional leaves,and the correlation was remarkably positive between the drooping angle of upper 3 leaves and the panicle length.Super hybrid rice had appropriate sink and enough sources,and the correlation of the spikelets per panicle was remarkably positive to the length of the flag and 2nd top leaves and the area of flag leaf,and the correlation of the number of unfilled grain per panicle was remarkably negative to the length and area of the functional leaves. Increasing sources unilaterally could have an adverse effect on the seed-setting percentage.The correlation was negative between the length,width and area of the upper 3 leaves and the seed-setting percentage,and it was remarkably negative between the length and area of upper 2 leaves and the seed-setting percentage.Among the relations between economic characteristics and leaf posture of super hybrid rice,the correlation was remarkably positive between the 1000-grain weight and basic leaf angle of the 2nd,3rd top leaf.The seedling numbers of droopy and loose super hybrid rice was difficulty to be increased,and the correlation was remarkably negative between the drooping angle of upper 3 leaves and the maximal seedling number.There were three kind of spike-grain constructions in the tested super hybrid rice combinations.Firstly,it was high grains weight with small panicle,for example, Zhunliangyou 527 had up to 31g of the 1000-grain weight and nearly 150 spikelets per panicle,and its average of seed setting rate was about 90%.Secondly,it was medium grain weight with medium panicle,for example,C liangyou 87 had nearly 28g of the 1000-grain weight and about 180 spikelets per panicle,and its averaged seed-setting rate was above 85%.Thirdly,it was low grain weight with big panicle,for example,Y liangyou1 and Honglianyou 6 had from 25 to 27g of the 1000-grain weight and from 180 to 200 spikelets per particle,and their average of seed-setting rate was above 85%.The number of effective panicles per plant of all kinds of the super hybric rice combinations was above twelve.
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