Studies On Germplasm Selection And Physiological And Ecological Characteristics Of Jatropha Curcas L.

In this paper, 151 different germplasms which from 37 provenances of Jatropha curcas L.that stored in Yuanmou Desert Ecosystem Research Station of the State Forestry Administration were taken as the study object. The pre-initial choice based on biological characteristics and economic indicators showed each kind of germplasm was to representative one germplasm.And a total of 20 kinds of germplasm for further excellent Germplasm Selection.From the aspects of biological characteristics, growth characteristics, physiological characteristics and economic indicators to study and compare the difference of germplasms, And to explore the correlation between economic indicators and characteristics. In order to find out the outstanding high yield and high oil seed s germplasms and the major physiological and ecological factors that affect the productivity of Jatropha curcas L.The main conclusions were as following:1)There are differences in morphology characteristics and reproductive phenology from the different Jatropha curcas L. germplasms. The average female and male flower number of single inflorescence from 20 Jatropha curcas L. germplasms were 9.2 and 131.3, Of which NO.9(Panzhihua-01)and NO.10(Lancang-04) had the largest number of female and male flowers,which were12.6,209.2 and 13.8,200.3 respectively.And the NO.11(Heqing-16) was least in female number(4.9),the NO.4(Nujiang-09) was least in male number(88.8). The NO.18 (JAS2-S2) was highest (10.3%) in sex ratio, the NO.4(Nujiang-09),NO.8(Yuanmou-02) had the largest number in inflorescences per plant, reaching 51.7 and 48.3. The diameter class division of the female flowers, male flowers and sex ratio showed a frequency of normal distribution, followed by the main distribution range of 5¹0, 81¹40 and 5%⁸%, all of its contribution to the value of the frequency were above 0.5.2)The average specific leaf area of 20 germplasms was 154.0cm²/g, of which the NO.2 (Honghe-06), NO16(Ningnan-01) and NO.3(Yuanyang-01) showed the specific leaf area of 187.3 cm²/g ,176.1 cm²/g and 171.7 cm²/g, were larger in all germplasms. The leaf area index of NO.4(Nujiang-09) was 5.5, Significantly higher than the other germplasm.Thus, they were able to use more space on the solar radiation, increase the accumulation of photosynthetic organisms. Furthermore, NO.2 (Honghe-06) and NO.4(Nujiang-09) germplasms were high in total chlorophyll content (2.345mg/g, 2.265mg/g) and chlorophyll / carotenoid value(11.131 and 21.182), low in chlorophyll (a/b) value(1.690 and 1.199), were easier to capture the light, make full use of external light and had high photosynthetic potential.3)The 20 germplasms of Jatropha curcas L. showed a pattern of two-peak in net photosynthetic rate in rainy season, showed peaks respectively at 10:00am(15.45μmol·m^-2·s^-1) and 16:00pm(11.26μmol·m^-2·s^-1),and the daily average net photosynthetic rate were 10.24μmol·m^-2·s^-1. The"midday depression"occurred in14:00pm for the reason of stomatal and non-stomatal effects. Different germplasm had different photosynthetic parameters, the germplasms of NO.2 (Honghe), NO.3 (Yuanyang-01), NO.6 (Hekou-01) had the largest parameters in light saturation point (LSP) and the maximum net photosynthetic rate (Pmax), LSP respectively showed in 2180μmol·m^-2·s^-1, 2076μmol·m^-2·s^-1, 2112μmol·m^-2·s^-1, and the maximum net photosynthetic rate (Pmax) respectively showed in 28.886μmolCO₂·m^-2·s^-1, 27.851μmolCO₂·m^-2·s^-1, 27.809μmolCO₂·m^-2·s^-1. So the three kinds of Jatropha curcas L. germplasms had a strong source of light contract capabilities, had a wide distribution area, with large area cultivation potential.4) Other physiological and ecological characteristics of the test germplasms showed that the germplasms of NO.1(Yuanjiang-09), NO.2(Honge-06), NO.4(Nujiang-09) were high in qP, Fv/Fm, F'v/F'm,ΦPSâ…¡and ETR. thus, they had a strong ability in photosynthetic electron transport and light energy capture. The germplasms of NO.5 ( Gejiu-03 ) ,NO.8(Yuanmou-02),NO.17(JAS2-S1)were high in qN low in qP, Fv/Fm, F'v/F'm,ΦPSâ…¡and ETR, so there had a strong potential in PSâ…¡heat dissipation capacity, and effectively prevent excess light damage on the photosynthetic apparatus, but the light use efficiency and photosynthetic capacity were low.5) The NO.4(Nujiang-09), NO.3(Yuanyang-01) and NO.8(Yuanmou-02) were high in inflorescence per plant. Thus, there were high in fruit yield per plant, seed yield, respectively 3 198.91g, 3 048.32g,1 958.75g, and 472.86g, 223.91g, 275.07g. The NO.4(Nujiang-09) also highest in hundred seed weight (61.58g), that high in all germplasms. The NO.8(Yuanmou-02), NO.16(Ningnan-01) and NO.4(Nujiang-09) were highest in all test germplasms in hundred kernel weight, shelling percentage and seed oil content,?were?42.61g, 62.8%, 44.41%; 47.99g, 65.74%, 44.14% and 44.71g, 66.1%, 40.88% respectively.6)There were significant positive correlation between economic traits and leaf area index(LAI), Chl content, the maximum net photosynthetic rate (Pmax), LSP, F′v/F′m.? Using principal component and regression analysis Established excellent germplasm selected multiple regression model: Y=-22.178+0.420X1+0.858X2-27.740X3-0.416X4. According to this model,the germplasms of NO.4(Nujiang-09), NO.3(Yuanyang-01), NO.8(Yuanmou-02), NO.2(Honghe-06), NO.6(Hekou-01) were the most outstanding germplasms .There were high in economic traits and excellent in physiological and ecological characteristics. And the selected results were basically consistent with the foregoing individual characters. Thus,?The selecting methods can be used both for the evaluation of elite germplasm and also be served as the basis for early breeding and methods.