Department of Agronomy and Horticulture, Brigham Young University, 84602, Provo, UT, USA.
Photosynth Res. 1987 Jan;11(3):201-9. doi: 10.1007/BF00055060.
Chrysothamnus nauseosus ssp. albicaulis (white rubber rabbitbrush) is a common deciduous C3 desert shrub which is a potential source of natural rubber and which exhibits high rates of net photosynthesis (Pn) for a woody species. When maintained under irrigated conditions in the field, rates of Pn on cloudless days were generally found to be highest during the cool morning hours (peak rates observed between about 0900 and 1000 hrs). Pn declined during mid-day hours and was approximately 75% of that observed in the early morning for the remainder of the light period. This decline in Pn was accompanied by about 26 μmol CO2.m(-2).s(-1) in mid-May (approximately 30 days after bud break) to about 48 μmol CO2.m(-2).s(-1) in early August. Thereafter, Pn declined gradually until leaf fall in November. These data indicate that rabbitbrush is capable of relatively high rates of Pn throughout a substantial portion of the growing season when maintained under irrigated conditions. This may, at least in part, account for the relatively high rates of growth observed under conditions of ample soil moisture.
黄花矶松亚种白毛（白色橡胶兔尾草）是一种常见的落叶 C3 沙漠灌木，是天然橡胶的潜在来源，并且表现出高净光合速率（Pn），这对于木本植物来说是很高的。当在田间进行灌溉条件下维持时，通常在无云的天气下，清晨凉爽的时段（观察到的高峰速率在 0900 到 1000 小时之间）的 Pn 速率最高。在中午时段 Pn 下降，并且在光照周期的其余时间，Pn 大约为清晨观测值的 75%。这种 Pn 的下降伴随着大约 26 μmol CO2.m(-2).s(-1)在 5 月中旬（大约在芽裂后 30 天）到 8 月初的大约 48 μmol CO2.m(-2).s(-1)。此后，Pn 逐渐下降，直到 11 月落叶。这些数据表明，当在灌溉条件下维持时，黄花矶松亚种白毛在生长季节的相当大部分时间内都能够保持相对较高的 Pn 速率。这至少部分解释了在充足土壤水分条件下观察到的相对较高的生长速率。
