离体穗培养条件下C、N供给对小麦穗粒数、粒重及蛋白质含量的影响

Effect of Carbon and Nitrogen Levels in Culture Medium on Grain Number per Spike,Grain Weight,and Protein Content of Wheat under Detached Spike Culture

为探究C、N供给时期和供给水平对小麦籽粒建成及蛋白质含量的影响,以冬小麦品种济麦22为材料,采用离体穗培养的方法,设置了三个蔗糖浓度(C1:20 g·L^(-1);C2:40 g·L^(-1);C3:80 g·L^(-1))和四个硝酸铵水平(N1:0.57 g·L^(-1);N2:1.14 g·L^(-1);N3:2.28 g·L^(-1);N4:4.56 g·L^(-1)),比较分析了开花期和花后7 d培养的小麦穗粒数、粒重及籽粒蛋白质含量对C、N供响应的差异。结果表明,1)开花期增加C、N供给可明显提高小麦穗粒数,C3的穗粒数相比于C1、N3的穗粒数相比于N1分别增加23.5%和8.2%,且弱势粒增幅显著高于强势粒,高氮(N4)下穗粒数显著下降,N4的强、弱势粒数相比于N3分别降低4.8%和29.6%;花后7 d增加C、N供给对穗粒数无显著影响;两个时期比较,以开花期培养的小麦穗粒数更高。2)开花期和花后7 d增加C供给均能显著提高小麦粒重,C3的粒重相对于C1分别提高84.9%和41.5%,且弱势粒增幅大于强势粒;开花期适当增加N供给也能提高小麦粒重,N3的粒重相对于N1增加10.2%,花后7 d适当增加N供给对粒重无显著影响,高氮(N4)下粒重显著下降,且以弱势粒降幅较大;两个时期比较,以花后7 d培养的小麦粒重较高。3)小麦穗粒重随培养基C、N浓度的增加而增加,但高氮下穗粒重显著降低,且穗粒重受粒重的影响较大。4)小麦籽粒蛋白质含量和蛋白质积累量随C浓度的增加而持续降低,随N浓度的增加而持续增加。综上可知,离体穗培养条件下C、N供给水平对小麦穗粒数、粒重及蛋白质含量的调控作用明显,其中开花期增加C、N供给的增粒增重效果更显著,以弱势粒反应更敏感;另外,穗粒数与粒重、粒重与蛋白质含量的调控具有一定矛盾性,其平衡协调仍需进一步研究。

In order to explore the effects of C and N supply period and supply level on wheat grain formation and protein content,winter wheat variety Jimai 22 was used as material.Three sucrose concentrations(C1:20 g·L^(-1),C2:40 g·L^(-1),and C3:80 g·L^(-1))and four ammonium nitrate levels(N1:0.57 g·L^(-1),N2:1.14 g·L^(-1),N3:2.28 g·L^(-1) and N4:4.56 g·L^(-1))were set up.The effects of C and N supply on the grain number per spike,grain weight and protein content of wheat grains cultured at flowering stage and 7 days after anthesis were compared and analyzed.The results showed that:increasing C and N supply at flowering stage significantly increased the grain number per spike.Compared with C1,C3 increased grain number per spike by 23.5%;N3 increased grain number per spike by 8.2%,compared with N1,where the increase rate of inferior grains was significantly higher than that of superior grains.N4 decreased grain number per spike by 4.8%for superior grains and 29.6%for inferior grains compared with N3 at high nitrogen level.The increase of C and N supply at 7 days after anthesis had no significant effect on grain number per spike.In comparison,grain number per spike of wheat cultivated at flowering stage was higher.Increasing C supply significantly increased wheat grain weight.Compared with C1,C3 increased grain weight by 84.9%and 41.5%at flowering stage and 7 days after anthesis,respectively;and the increase rate of inferior grains was greater than that of superior grains.Proper increase of N supply at flowering stage also increased grain weight of wheat.Grain weight under N3 was increased by 10.2%compared with that under N1,but properly increasing N supply at 7 days after anthesis had no significant effect on grain weight.Grain weight was decreased significantly at high nitrogen level(N4),and the decrease rate of inferior grains was larger.The grain weight of wheat cultured 7 days after anthesis was higher.The results showed that the grain weight per spike increased with the increase of C and N concentration,but decreased significantly under high nitrogen,and was greatly affected by grain weight.The protein content and protein accumulation of wheat grain decreased with the increase of C concentration,but increased with the increase of N concentration.In conclusion,the regulation of C and N supply level on the number of grains per spike,grain weight and protein content of wheat in vitro was obvious.The effect of increasing C and N supply at flowering stage was more significant,and the response of inferior grains was more sensitive.In addition,the regulation of grain number per spike and grain weight,grain weight and protein content were contradictory,and the balance and coordination of them still needs to be further studied.