不同水分条件下小麦ILs群体花后不同器官蔗糖积累与转运的遗传特性

为了探索干旱调控小麦花后不同器官蔗糖积累和转运的遗传特性,以抗旱性有显著差异的西峰20和鲁麦14杂交创建的小麦回交导入系(introgression lines,ILs)群体为供试材料,对正常灌溉(WW)和干旱胁迫(DS)条件下该群体花后不同器官蔗糖积累和转运的相关性状进行数量遗传分析,评价该群体目标性状的遗传变异特点和相互关系。结果表明,小麦ILs群体及其双亲的被测性状指标均表现为SCg(灌浆期蔗糖含量)显著高于SCf(开花期蔗糖含量)和SCm(成熟期蔗糖含量),主茎穗下节和倒二节的蔗糖含量高于旗叶,花前高于花后,干旱胁迫显著高于正常灌溉。在两种水分条件下,小麦ILs群体各被测性状平均表型值均介于双亲之间,且偏向于轮回亲本鲁麦14;群体内表型变异广泛,且存在超亲分离,变异系数为14.29%~57.98%(DS)和20.87%~63.75%(WW),多样性指数为0.63~0.89(DS)和0.57~0.79(WW)。各目标性状表型受水分和发育阶段/器官的影响达显著水平,遗传力较低,为0.27~0.51(DS)和0.30~0.62(WW)。各器官的SCf、SCg和SCm间均有不同程度的正相关(r=0.17~0.56**)关系,SCf与花前蔗糖转运率和花后蔗糖贡献率(r=0.32**~0.94**)、SCg与花前蔗糖转运率和花后蔗糖贡献率(r=0.29*~0.72**)、主穗粒重与花前蔗糖转运率和CRSpr(r=0.13~0.43**)具有较高正相关性,且各目标性状间DS条件下相关系数普遍高于WW。说明小麦花后不同器官蔗糖积累和转运相关性状属于典型的数量性状,其表型变异具有显著的时空特异性。

Genetic Analysis of Accumulation and Translocation of Sucrose in Different Organs after Flowering in Wheat ILs Population under Different Water Conditions

In order to reveal the genetic characteristics of accumulation and translocation of sucrose in different organs after flowering,an introgression lines(ILs) population derived from a backcross between two wheat cultivars(Xifeng 20 and Lumai 14) with different drought tolerance was used to evaluate quantitative genetic variations and correlations among target traits under well-watered(WW) and drought stress(DS) conditions.As for the phenotypic values of target traits in the ILs and two parents,the results showed that SCg(sucrose content of flowering) was significantly higher than SCf(sucrose content at grain-filling) and SCm(sucrose content at mature).Sucrose content in peduncle and penultimate internodes of main shoots were higher than that in flag leaf.Pre-anthesis and DS had higher sucrose content,compared to post-anthesis and WW,respectively.Under two water conditions,the phenotypic means of all target traits in the ILs were intermediated between those of two parents,but tended to be closer to the recurrent parent Lumai 14.The phenotypic values of all traits in the ILs varied widely,altogether with presenting substantial transgressive segregation.The coefficients of variations ranged from 14.29% to 57.98% under DS and from 20.87% to 63.75% under WW,while the genetic diversity indices differed from 0.63 to 0.89 under DS and from 0.57 to 0.79 under WW.The phenotypic variations of all traits were significantly affected by water conditions and growth stages or organs.The heritability of all traits was lower and varied from 0.27 to 0.51 under DS and 0.30 to 0.62 under WW.There were variously positive correlations(r=0.17-0.56^**) between SCf,SCg and SCm in different organs.SCf was highly correlated with RRSpr(translocation rate of sucrose during pre-anthsis) and CRSpr(contribution rate of sucrose during pre-anthesis)(r=0.32^**-0.94^**),and SCg was correlated with RRSps(translocation rate of sucrose during post-anthesiss) and CRSps(contribution rate of sucrose during post-anthesis)(r=0.29^*-0.72^**),and SGW(main spike grain weight) was positively correlated with RRSpr and CRSpr(r=0.13-0.43^**).The correlation coefficients under DS were significantly higher than those under WW.This indicated that related traits to the accumulation and translocation of sucrose after flowering in different organs in wheat were quantitatively inherited,of which phenotypic variations showed significantly temporal-spatial specificity.