天津沿海滩涂互花米草种群生殖分株数量特征及生殖分配研究

通过对天津沿海滩涂单优群落的取样调查,研究了互花米草种群生殖分株的数量特征和生殖分配规律。结果表明,在籽实成熟期,互花米草种群单个生殖分株重为15.62±9.26 g,穗和种子重分别为2.68±2.08和1.39±1.12 g,小穗和种子数分别为537.7±362.2和490.2±376.3个,生殖分配Ⅰ和生殖分配Ⅱ分别为15.02±5.83和7.62±3.8%,结实率为81.9 ±28.6%。穗和种子的形成分别需要分株积累3.2和3.6 g以上的生物量。穗长、穗重、种子数、小穗数、生殖分配Ⅰ和生殖分配Ⅱ分别与分株高度呈极显著(p<0.01)的正相关关系。穗重、小穗数、种子重、种子数、生殖分配Ⅰ和生殖分配Ⅱ分别与分株重呈极显著(p<0.01)的线性正相关关系。种子数、小穗数、生殖分配Ⅰ和生殖分配Ⅱ分别与茎和叶鞘生物量分配呈极显著(p<0.01)的负相关关系。穗各构件在空间上的分布也存在较强的规律性。

Quantitative Characteristics and Reproductive Allocation Study on Reproductive Ramets of Spartina alterniflora Population in Tidal-flat in Tianjin,China

Through sampling measure on the single dominant species community in tidal-flat in Tianjin, the quantitative characteristics and the reproductive allocation on reproductive ramets of Spartina alterniflora population were studied in the ripening stage. The results showed that the w-eight of each reproductive ramet of Spartina alterniflora population was 15.62±9.26 g; the weight of ear and seeds were respectively 2.68±2.08 and 1.39±1.12 g; the number of spikelets and seeds were respectively 537.7±362.2 and 490.2±376.3; reproductive allocationⅠ(RAⅠ) and reproduc tive allocation Ⅱ(RAⅡ)were respectively 15.02±5.83 and 7.62±3.8%; the seed percentage was 81.9±28.6%. It is necessary to accumulate total biomass of ramet, which was more than 3.2 and 3.6 g for producing ear and seeds, respectively. There were most significant positive correlations between the length of ear and weight of ear and number of spikelets and seeds and RA Ⅰand RA Ⅱ and the height of ramet, respectively(p<0.01). There were most significant positive correlations between the weight of ear and seeds and number of spikelets and seeds and RA Ⅰand RA Ⅱ and the weight of ramet, respectively(p<0.01). There were most significant negative correlations bet-ween the number of seeds and spikelets and RAⅠand RA Ⅱand the allocation of stem and leaf sheath biomass, respectively(p<0.01).The regularities of the spatial distribution of ear are obvious.